Clinical Efficacy of Hibiscus in Improving Iron Status in Patients with Anemia

Anemia, defined as a hemoglobin (Hb) serum concentration of <11.0 g/dL at sea level, is usually caused by low intake and absorption of dietary iron. Anemia currently affects roughly 67.6% of the population in Africa, many of whom are concurrently exposed to malaria. In Tanzania, hibiscus (Hibiscus sabdariffa, Malvaceae) flower and calyx infusions or juices are among several natural products used for anemia. Hibiscus contains several minerals, including iron, and ascorbic acid, which is known to increase iron absorption. In vivo, an aqueous extract of hibiscus significantly increased hematocrit (Hct) and Hb levels. Clinical trials have evaluated its use in lowering cholesterol, reducing hypertension, and controlling type 2 diabetes; however, none have examined its effect on iron deficiency. Therefore, these authors conducted a randomized clinical trial to measure the effect of hibiscus extract on iron status in patients with anemia.

Hibiscus calyxes were collected from local farms in March 2014, with a voucher specimen deposited in the herbarium of the Botany Department, University of Dar es Salaam, Tanzania. An aqueous extract optimized for both ascorbic acid and iron extraction was prepared to contain 0.831 mg/g L-ascorbic acid and 0.078 mg/g iron. The extract was issued to patients in 10-day dose packs with instructions.

Of the 202 individuals screened, 130 who were eligible (aged 18-50 years, Hb between 8.0-12.9 g/dL for men and 8.0-11.9 g/dL for women [anemic], no use of vitamin or mineral supplements for 30 days before enrollment, no organ impairment, no chronic illness, no blood given or received in prior 6 months, not pregnant or nursing, residents of study area, no history of serious medical conditions, and no participation in any investigational trial for 90 days before the study) were randomly assigned into 4 groups with similar proportions of key characteristics (e.g., gender, age, and Hb levels) in each.

Patients in group D1 (n=35) drank 1 L of the product daily; those in D2 (n=34), 1500 mL; and those in D3(n=32), 2 L. Patients in D4 (control; n=29) took 200 mg ferrous sulphate yielding 65 mg ferrous iron daily. Primary endpoint was changed in iron status indicators (Hb level, serum ferritin [Fer], and Hct parameters [mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), and red cell distribution width (RDW)]) between baseline and end of follow-up. Vital signs, laboratory tests, and questionnaires were used at baseline and at clinic visits every 10th day. Tests included complete blood count, renal and liver function tests, and hematology. Adverse events were assessed and classified as mild, medium, or severe. Compliance was monitored through home visits by village health workers in addition to clinic visits.

Patients, from 8 villages in Mkuranga District, Tanzania, had a mean age of 37 ± 11.8 years; 79 (60.8%) were women. About 20% had been ill in the 12 months before baseline, with urinary tract infections most common (41.7%). About 34% were using antibiotics at baseline; 32.7%, analgesics. “A significant proportion” of patients with no reported illness was taking medicine. There were no significant differences among groups in red blood cell characteristics, nutrition, or inflammatory markers at baseline (P>0.05 for all). After 4 weeks, 82 patients remained in the study—18 in group D1, 24 in D2, 21 in D3, and 19 in D4. A total of 37 were lost to follow-up for unknown reasons; others, for medical reasons or by moving away. Malaria (58 cases) did not cause any cited dropouts. Baseline data on malaria status are not provided.

In this study, the hibiscus treatment was not effective in treating anemia, but showed potential for improving hematological parameters. Fer levels rose significantly in D4 (control; P=0.0014) compared to baseline; in other groups, nonsignificantly (P>0.05). RDW fell, although nonsignificantly, in all groups compared to baseline, most noticeably in D3 (P=0.2754). There was a significant decrease in MCH in D1, D2, and D4 compared to baseline (P<0.05 for all); in D3, there was a nonsignificant decrease in MCH (P=0.0571). In D1 and D4, significant declines in Hb were seen compared to baseline (P=0.0123 and P=0.0219, respectively). [Note: In the article text, the value for D1 is given as P=0.123.]

The authors call for studies with larger populations. Findings differ from a study of hibiscus and pineapple (Ananas comosus, Bromeliaceae) juice, with an average increase in Hb after 9 days that exceeded conventional anemia treatment (+2 g/dL in 3 weeks). Additional studies are also needed to examine the complex comorbidities of anemia and malaria. A recent study in Tanzania found that “iron deficiency appears to protect against both malaria infection and mortality.”1,2


1Richards S. Iron deficiency protective against malaria. The Scientist website. Available at: Published April 13, 2012. Accessed October 4, 2017.

2Gwamaka M, Kurtis JD, Sorensen BE, et al. Iron deficiency protects against severe Plasmodium falciparum malaria and death in young children. Clin Infect Dis. April 15, 2012;54(8):1137-1144.

Peter EL, Rumisha SF, Mashoto KO, Minzi OMS, Mfinanga S. Efficacy of standardized extract of Hibiscus sabdariffa L. (Malvaceae) in improving the iron status of adults in malaria endemic area: a randomized controlled trial. J Ethnopharmacol. September 14, 2017;209:288-293.


Creating A “Welltality” Garden

Gardeners looking for a place to unwind, meditate, and rejuvenate will enjoy this new landscaping trend, which combines elements of healing, privacy, and sensory experience to create a meaningful way to tune out the daily grind.

Busy schedules, constant texts, and tweets, the demands of work, and balancing a fun, happy family life can pose a challenge. Finding time and a quiet spot to relax and focus on your wellbeing isn’t always easy, but your garden provides a good place to start. By keying in on five vital essential elements – “soundscaping,” tranquility, healing plants, sensory stimulation, and privacy – you can easily turn your yard into a healthful retreat for friends and family that gives you the opportunity to relax, unwind, and embrace a little free time in a meaningful way.


City and suburban life can be hectic and incredibly noisy. While some people may grow accustomed to the din, urban life bombards its residents with the sheer volume and complexity of the surrounding noise. Studies of Boston, Los Angeles, and New York show that the decibel levels in an average restaurant range from 88 to 92, and the noise in the New York subway can hit a whopping 106 decibels {sounds above 85 are considered harmful}, according to the consumer information site Elevating Sound. The term soundscaping refers to the use of plants and other natural materials to block out unwanted noise while promoting natural sounds such as birds, insects, water, and the wind.

Plants with Height: If you have the planting space and don’t mind the shade they create, tall trees are the easiest way to muffle noise. Conifers such as spruce, pine, and fir make obvious choices because of the density of their branches and needle-like foliage, and the fact that they branch all the way to the ground {unlike many deciduous trees}, which effectively walls off the sound.

A combination of deciduous trees and an understory of shrubs or herbaceous perennials and large herbs such as Echinacea, Monarda, and Joe-Pye weed will work as well. To enjoy the gentle rustling sound in a breeze, consider deciduous trees with large leaves, such as aspen, linden, or birch.

Hedges will create the same “wall” effect, but without the height of conifers {or the space required}. Try sturdy, easy-maintenance hedge plants such as cotoneaster, yew, or alpine currant. As a bonus, many hedge plants encourage birds to the garden with the fruit, seeds, and safe habitat they provide.

Sound Screens: A green or “living” wall is also an option. You can build these using a variety of materials, from wooden pallets to stacked stone to elaborate hydroponic systems. Include a variety of species: succulents; mosses; alpine and creeping varieties such as saxifrage, sea thrift, and Lewisia spp.; and trailing vines like Vinca minor, licorice plant, and moneywort. Living walls also create privacy and security, and they’re flexible enough to move around the garden, depending on where the sun beams down.

Sound Absorption: To dampen loud noises, we can look to groundcovers. Turfgrass is an obvious choice, but you can think outside the box with cultivars of flowering and fragrant creeping herbs like thyme, savory, violets, clover, and houseleeks. Many of these plants can withstand foot traffic and, as a bonus, often attract pollinators such as bees!

Soothing Sounds: Substituting a stressful sound with a soothing one offers another way to the soundscape.  If you have the budget and room {as well as the ability to keep up with the maintanence}, you might build a small pond with a fountain or stream. A simple, decorative tabletop fountain can add soothing trickling sounds to a patio, deck, or balcony for a lot less money and effort.

In some areas, homeowners can have fire pits or decorative fire bowls in their backyards {as long as safety protocols are followed}. Most people consider watching the flames and listening to the sounds of a crackling fire a relaxing past-time, particularly on cool evenings.

A Time for Tranquility

Where you decide to place your garden is another important consideration.

Shade & Shelter: A space that sits in dappled shade offers a more hospitable environment than one in hot, bright sunlight, but it will limit plant selection. Chives, parsley, tarragon, and sweet woodruff do perform well in partial shade, and you can choose shrubs and small trees such as dogwoods, viburnums, cotoneaster, and willows. But assuming you don’t want to miss out on those sun-loving plants, then hardscaping items like an umbrella or canvas canopy should do the trick of keeping you cool. Make sure to situate your garden in a sheltered location, away from strong winds.

Garden Plan: The style of the garden will also influence the way you feel as you interact with it. For example, informal, curved pathways, and rounded edges are easier on the eye and mind than harsh lines and a grid-like structure.

Of course, the right plants will also help you unwind. Try a subdued color palette: instead of bright oranges, yellows, and reds, look for flowers in cooler shades of blue, purple, white, and silver. Artemisia, marshmallow, thyme, and meadowsweet are all good options. Focus on the foliage, including complementary colors and leaf variegation. {Some variegated herb options: ginger mint ‘Variegata,’ lemon balm ‘Aurea,’ buddleia, and the variegated cultivar of pineapple sage.} Avoid spiky, thorny, or otherwise aesthetically harsh and jarring features, and look instead to soft or fern-like leaves such as sweet cicely, dill, caraway, and chervil.

Hardscaping: Statuary and garden ornaments can make statements in any wellness garden. Choose pieces that reflect both space and your personal style, and that makes you smile when you see them. Finally, don’t forget to add a seating area to your tranquility garden – you will, after all, be spending a lot of time in it!

Perfected Privacy

Any garden that provides a restful “haven” from the bustle of everyday life should also include a sense of security. Since ancient times, walled gardens have offered quiet places for reflection and relaxation -away from the prying eyes of others.

Better Barriers: There are several ways to create enclosure within the garden. Hardscaping elements like fences and courtyards are obvious ones, as are decks, patios, and balconies. Living walls, potted trees {citrus, figs, Japanese maples}, and vines such as clematis, trumpet vine, morning glory, or Thunbergia can further enhance the space and increase privacy.

You might also employ plants to create living screens to demarcate outdoor “rooms” or cover up an unwanted view. Try honeysuckle or climbing roses trained to grow over an arbor, trellis, or lattice fence.

Plant Perimeters: On a smaller scale, plants such as phlox, marigolds, snapdragons, and dianthus used as edging or in the borders of flowerbeds can also lend a sense of visual enclosure, creating divided spaces in miniature. A labyrinth of lemon or creeping thyme, or with Irish and Scotch moss, is another example of how successful this idea can be -and as a bonus, you can use it as a walkable meditation tool!

Healing Help

A welltality garden certainly can’t exclude medicinal plants! You don’t need a lot of space -just room enough to include some important herbs. This quick list covers a range of conditions:

  • Thyme: a versatile culinary herb that’s also useful for soothing sore throats and freshening breath.
  • Rosemary: a Mediterranean culinary staple with aromatic qualities that improve cognitive function and promote mental alertness.
  • Roman chamomile: in tea, it decreases anxiety and encourages relaxation.
  • Calendula or pot marigold: Often used in cosmetics, it quiets irritated skin and clears acne. As a tea, it aids in digestion.
  • Lavender: Dried leaves are commonly used to stuff pillows, and the essential oil creates a relaxing room spray to encourage untroubled sleep. Like calendula, lavender is sometimes used to heal acne.
  • Peppermint: another staple of the healing garden {keep it contained so it doesn’t spread aggressively!} that calms an upset stomach when taken as a tea.
  • Bearberry: The tea combats urinary tract infections in low doses.
  • Bee balm: Sometimes employed as a soothing remedy for colds and sore throats.
  • Anise: Used as a tasty digestive aid and to treat stomach ailments.

Sensory Stimulation

This element of the garden aims to stimulate the five senses: sight, smell. touch, taste, and sound. Sensory gardens are often considered particularly suited to children, the elderly, and the infirmed – but everyone can benefit from the activity, education, and interaction with living plants and the natural world.

Sight: Visual appeal may be achieved through the use of color. If you want to promote a soothing, restful aesthetic, set up blocking of the same color {or shades of the same color}, using plants of the same species or those that complement one another. Alternatively, a garden space filled with contrasting colors, textures, and varieties of plants will impact the viewer, offering a creative way to open the mind and encourage exploration.

Sound: We’ve already discussed blocking and muting the unwanted sound, but here we want to encourage sound as a way to stimulate the mind. The delicate music of wind chimes or the splash of a fountain or other water feature is excellent ways to achieve this. Certain plants can also promote beneficial sounds: consider the wind rustling through ornamental grasses {showy, large species such as pampas or feather reed grass ‘Karl Foerster’}, or tall, leafy herbs including dill, lemongrass, Russian sage, angelica, and borage.

Scent: The fragrance of certain herbs and flowers can have a huge impact on mental alertness, emotion, and the creation of olfactory memories. Select highly fragrant and appealing plants for the sensory section of your garden: rose, mint, lavender, anise hyssop, basil, and sweet peas all work well. Don’t forget that most of these wonderful flowering plants also attract butterflies and bees, so focus on planting a diverse mix of species for best results.

Taste and touch: In a complete sensory garden, you want to include flavor and texture, but if your garden is open to others, you may want to have signage that lets visitors know which plants are edible and safe to touch {avoid planting toxic species in a wellness garden design!}. Besides fruits and vegetables, plant edible and beautiful herbs and flowers such as pansies, lemon balm, and nasturtium. Touchable plants with varied textures include soft, furry lamb’s ear, spiky yarrow, coneflower, and feathery fennel.

Tending to Your Garden

Care and maintenance of your welltality garden depend on the size and scale of your plantings, as well as the needs of individual plants. Keep up with regular watering, fertilizing, and weeding, and routinely check all plants for evidence of pests and diseases. Try not to look at these tasks as chores, but rather as an invitation to mindful participation in the growth of your garden. And even though it’s hard to resist placing plants where you would prefer them to grow, especially in a garden as expansive as this, those sited properly according to their requirements for sun, soil, and water will perform much better.

Make sure, too, that you have a combination of seating areas for contemplation, along with walking paths providing access to all parts of the garden. You want your visitors to fully immerse in the surrounding environment.

With thoughtful planning and attention to these five elements, your welltality garden is sure to be a nourishing, sustaining place to relax and enjoy!




Hibiscus Plant Care: Spider Mites

Spider Mites

My Hibiscus Leaves are Turning Yellow!

Yellow Leaves on an Otherwise-Healthy Plant
The First Sign of Spider Mites

Spider mites are a warm weather problem for many hibiscus growers. They prefer hot, sunny, dry conditions and their levels can soar when the temperatures rise. If not dealt with they can cause all the leaves of a hibiscus to fall off and seriously damage the overall health of the plant.

How Can I Tell if My Hibiscus Have Spider Mites?

The first sign of spider mites is yellow leaves. A leaf or two first gets yellow mottling mixed in its normal green, then slowly the entire leaf turns bright yellow. At first, you just see a few yellow leaves, here and there, and don’t think anything of them. But very soon the spider mite population explodes and more and more leaves turn yellow at an increasing rate of destruction.

Spider Mite Webs in Bright Sunlight

As the spider mites spread, they become visible to the naked eye only in the brightest light with the closest inspection. A magnifying glass helps immensely at this stage. Look at the tips of the branches with yellow leaves, and you will see very fine webbing. These are the spider mites’ webs. You can sometimes see little dots on the webs – the spider mites themselves. At this point, you have a severe infestation that must be dealt with quickly or these little pests will make every leaf on your plants turn yellow and fall off, which can eventually kill the hibiscus.

Tell-Tale Signs of Spider Mites

An Advanced Case of Spider Mites
Look Closely to See the Webs & Mites on Growing Tips
Leaves Show the Typical “Mottling” of Green & Yellow

Tiny Spider Webs: Look for tiny spider webs on the growing tips of your plants. You will need to look very closely, in bright sunlight, for very fine, tiny webs on the smallest growing tips or developing buds. If you have good eyes and bright light, you may see tiny dots along the webs. These are the spider mites. With a magnifying glass, you can see that the dots actually look like tiny crabs scuttling along the web.

Growing hibiscus in the house or in a greenhouse offers a lot of protection from many forces of nature, including pests like thrips, ants, slugs, and even aphids much of the time. However, there is one bug that thrives in the warm conditions of the greenhouse and positively flourishes in the warm, dry environment of a house – the spider mite. The warmer and drier the environment, the more these little critters reproduce! So if your hibiscus is still indoors, watch carefully for signs of them.

Stippled Leaves: Leaves become stippled as the mites pierce the leaves and draw out chlorophyll from them, leaving colorless leaf spots behind. If you start to see leaves that look like this, with yellow stippling, search for spider mite webs on the stem tips.

Leaf Stippled by Spider Mites

Yellow Leaves: If the infestation continues, leaves that are badly infested will turn yellow and fall off. For many people, yellow leaves that fall off their hibiscus is the first clue that something is wrong. But by the time the infestation reaches this stage, it is already quite advanced. It’s best to learn how to detect spider mites in the earlier stages.

Sick Plant: If the spider mite infestation continues unchecked, the whole plant begins to look tired, with the leaves slightly drooping despite being well watered.

Defoliation: If left untreated the mites can create a mass of webbing over the plants, and most or all of the leaves will become damaged, turn yellow, and fall off.

How Do I Get Rid of Spider Mites?

Plant Defoliated by Spider Mites

Over the years, we have written many articles on how to control spider mites. The methods below are the ones we have found to be most effective at killing spider mites with the least amount of harm to the hibiscus plants. The method each of us chooses depends on the circumstances – how many hibiscus plants we have, how big the plants are, whether they are indoors or outdoors, in a house or greenhouse, in pots or in the ground, etc. At HVH we have hibiscus growing in the greenhouse, on the ground in an outside garden, indoors in a house environment, and outside on porches and decks in pots. We use different pest control methods for each of these different sets of hibiscus. Very few of us have extra time to waste, so efficiency matters! All of these methods work. It’s just a matter of finding the method that is quickest, easiest, and most efficient for you hibiscus and their growing circumstances.


This is our favorite method for all hibiscus growing in small-medium pots and for houseplant hibiscus. You only have to do it ONCE to kill all spider mites and their eggs. It kills every kind of spider mite, even the most microscopic ones that can hide in cracks in the bark. This method does require precision and care. You’ll need a timer and a thermometer – a kitchen “candy” thermometer is perfect. If the water is too hot or you leave the plants too long, you can damage the leaves and they will all fall off after treatment. If the water is much too hot and you leave the plants much too long, you could actually kill a very young plant. But if the water is too cool or if you don’t leave the plants in the water long enough, you won’t dissolve the covers of the eggs and kill the growing larvae, which means the infestation will come right back.

A Large Sock on a Small Pot
  1. Wrap the hibiscus plant pots in some kind of fabric and use a twist tie to secure the fabric around the base of the plant. The fabric must let water through, so don’t use plastic bags, or you will carefully protect any pests that are living in the pot and soil. Large socks or pantyhose work well to wrap up small pots, and pillow cases work well for large pots.
  2. Lay several hibiscus plants on their sides, pots and all, in a bathtub. You can put many of them close together in a single layer in the bottom of the tub.
  3. Fill the tub with water that is bath water temperature – about 90°F (32°C). It should not be so hot that you can’t comfortably keep your skin in it. What feels too hot to the skin will risk damaging your plants’ leaves.
  4. Fill the tub until all the plants are covered, and weight the plants down to make sure all parts of all plants are submerged in the water. (An easy way to weight them is to cover the plants with two large towels, then to pull the two shelf racks out of your oven and lay those carefully over the top of the towels.)
  5. Leave the plants submerged in the water for 45-60 minutes.
  6. Drain out the water and stand the plants up in the tub until the excess water drains out of the pots.
  7. Remove the fabric covers, and scoop any loose soil in the fabric back into the plant pots.
  8. Leave the plants out of bright light for a few hours to rest, then put them back where they belong. Be careful not to water the plants again until the soil dries out after this thorough soaking.

Unless plants are recontaminated by exposure to another infected plant, plants should remain free of spider mites, aphids, and other pests for 4-6 months or more. This method has the added advantage of leaching out any build-up of fertilizer salts in potted plants, which needs to be done once or twice a year. So it is two plant-care activities in one.



If your hibiscus is too big to put in a sink or bathtub, an alternative method is to wash your plants in a shower, under a faucet, or with a hose or BugBlaster. If done carefully and conscientiously, this method will wash off and drown adult spider mites, but it will not wash off or drown all eggs and nymphs. So you will have to repeat it 3-4 times, every 5-7 days, to get rid of all the spider mites as soon as they hatch out and grow into adults.

This method works for large hibiscus in pots or for hibiscus planted in the ground. It’s especially good for people with smaller hibiscus collections, because it is very effective, and it is the least damaging to plants and to the environment. It is time-consuming though; each plant must be washed slowly and carefully.

  1. If plants are in pots, lay them on their side where the pots can be rolled over to all sides. If plants are in the ground, get a long enough hose that you can walk all around each plant.
  2. Using a hard stream of water, wash every single millimeter of each plant – the top and bottom of every single leaf, branch, stem, and twig. Spray systematically, making sure you don’t miss one spot on the plant where spider mites could be lurking. Spider mites live mostly on the bottoms of leaves, so spraying the bottom of each leaf carefully is crucial.
  3. When finished, wash the ground with a very strong stream of water and enough water to drown any spider mites that fell off the plants.
  4. Repeat this washing process 2-3 more times every 5-7 days.


Another alternative method is to treat with either a miticide, such as Bayer Advanced 3-in-1 or with Horticultural Oil or Neem Oil. All three treatments work equally well, in our opinion, and we sometimes alternate between them, using one one week and the other the next week. Just like the washing method, sprays are effective at zapping adult spider mites, but in our experience, they don’t kill all the eggs or nymphs. So you have to repeat the spraying every 5-7 days for 3-4 egg-hatching cycles to make sure you get every emerging adult spider mite.

Breathing any of these products is very bad for you, so if you decide to spray, you should absolutely use a respirator mask. Oil droplets aren’t poisonous, but breathing oil into your lungs is very harmful to your body. You can feel it in your lungs for quite a while afterward if you make this mistake! It takes a lot of spraying to kill all the spider mites, and that amount of spraying without a mask is definitely bad for lungs.

One more note about spraying: All these products are best sprayed in the evening when the plant can be protected from the sun for the hours that the products are doing their work. If you spray in the evening, the products have 8-12 hours to work, and the sun won’t burn the products into plant leaves and burn them or harm them in any other way.

  1. Put your hibiscus in a protected place outside with enough space to walk all around each plant.
  2. Put on your respirator mask.
  3. Carefully and systematically spray every millimeter of the plant: tops and bottoms of every single leaf, stem, branch, and twig, as well as the surface of the pot and soil. It takes time to spray this carefully, but you may as well not bother spraying at all if you don’t do it this carefully! Spider mites living mostly on the bottoms of leaves, so spraying the bottom of each leaf carefully is crucial.
  4. Let the spray product dry for several hours before bringing the plants back into a house.
  5. Repeat this spraying process 2-3 more times at intervals of 5-7 days.

The trick with pest control is conscientiousness. Any one of these methods will work if applied conscientiously following the directions exactly. So find the method that’s easiest and most comfortable for you to follow.

Building a Low-Cost Greenhouse

Eventually, almost everyone who grows tropical plants comes to the conclusion that it would be very nice indeed to have a greenhouse to move their tropical plants into in winter. Not only is winter protection very desirable, but a greenhouse also extends the blooming season and helps the plants get an earlier start in spring. Yes, a greenhouse would be nice, but surely it would cost too much and take too much expertise to set up. Wouldn’t it?

Not at all. Greenhouses come in every conceivable size and price range. In the end what they do is trap the energy of sunlight inside a room that quickly warms up in response. There are more ways than one to achieve this, and they aren’t all expensive, nor do they require expert construction skills. This article will take a look at the subject of greenhouses, and make some suggestions for those of you who may be ready to take the plunge.

At the top end of the price range, there are very beautiful and functional greenhouse units that can be purchased fully equipped and installed on your property by a contractor. We’re not going to talk about those. If you’re interested in one of these, you can acquire catalogs from a number of suppliers and start your search. Some of the information below will still be of interest to you, because whether your greenhouse costs $50,000 or $500 it still needs to be able to accomplish many of the same tasks.

The Very Simplest Greenhouse Frame
One-Inch PVC Pipe Bend into a Hoop

This article will focus on “do-it-yourself” or “my-spouse-will-do-it-for-me” type greenhouses. You can build a surprisingly functional greenhouse with materials that are not expensive and are easy to work with. Home Depot and other similar home supply stores have most, if not all, of the materials you need. Since there are so many variations and so many individual circumstances, we are not going to try to give a step-by-step manual like we did with the drip system a few months ago. Rather, we will take a look at the features that any greenhouse needs to include and a few nice-to-have options as well.

One other note: This article is not about greenhouses for places where snow loads are high. That is a special circumstance that requires good design and materials that can take heavy snow loads. You can still have a home greenhouse in snowy areas, but unless you are an expert at construction, you probably will need to have a contractor build your greenhouse according to the needs of your area. This article is for greenhouses in areas that have some winter freezes, perhaps an inch or so of snow from time to time, but not blizzards and several feet of snow each winter. If you need a greenhouse for heavy snow loads, contact a company that supplies these types of greenhouses to obtain one that fits your locale.

Where To Start?

First, let us consider size. If you live in an area that is heavily regulated by zoning or subdivision rules, you should check those before you build the greenhouse only to have someone complain that it is too big or too high or not allowed at all. Assuming you are good to go, then how big a greenhouse do you need? It is a rare person who builds a greenhouse and then finds that it is too big for their needs. The opposite is almost always the case – your plant collection will rapidly grow to fill it, and you will be looking for more space. So, the best thing to do is to build as big a greenhouse as you can in the space you have available or build it with the idea that you will add onto it as needed. Greenhouses are wonderful additions to a home property and can provide many hours of pleasure while the weather outside is rotten and cold. Build it as big as you dare!

What to Build The Frame Out Of

A PVC Greenhouse Frame

There are three main types of materials used for building greenhouses at home. These are:

  1. PVC Pipe:

    Yes, common PVC pipe that is used in irrigation systems makes a fine frame for a small greenhouse. It is cheap, easy to work with, has all sorts of available connecting pieces to accommodate almost any design, and is lightweight. The light weight can be a problem in high wind areas because the greenhouse can blow away. So in windy areas, the plastic covering may need to be removed during the stormy summer months to help prevent this.

  2. Wood:

    Stronger and more stable, but also more expensive unless you have access to cheap wood. A wood-framed greenhouse requires some basic carpentry, and it helps if you have some basic power tools and a little experience working with wood.

  3. Metal:

    The strongest and longest lasting material for the frame. This would seem to be outside the reach of most people, but in reality, it’s not. There are several suppliers that provide pre-drilled metal parts, including all connectors for constructing even small greenhouses at quite a reasonable price. This is a very good option for those who want to have a somewhat larger structure, say 24 feet wide by 48 feet long or bigger.


A Metal-Frame is Best for Large Greenhouses

The Floor

The greenhouse floor does not have to be totally flat nor do you have to grade a perfectly horizontal surface for it. I have had greenhouses on the side of a hill and they still work just fine. It is easier to build the greenhouse “square” if the surface is level, but if you cannot make a level location, you can still build your greenhouse. A slight slope inside the greenhouse is actually beneficial because excess water will flow more quickly out of the greenhouse.

Prepping a Greenhouse Floor

We should really call this the “floor” rather than the “foundation”. It is not at all necessary to pour a concrete foundation for a greenhouse. Water run-off is always an aspect of having a greenhouse full of plants. If there is a concrete floor, the water cannot sink into the ground and must find some other way to exit the greenhouse. If you must have a concrete floor, then think through how the excess water is going to be removed from the greenhouse.

If building on the ground, lay a layer of weed barrier cloth directly on the ground, cover it with an inch or two of gravel and finish it with a second layer of weed barrier cloth on top of the gravel. This will allow water to sink into the earth, and prevent weeds from growing in the greenhouse. It also provides a decent surface for walking and working. You could skip one or both layers of weed barrier and just put down the gravel, but that is not a good solution unless the budget is too tight to do it any other way.

The Covering

Polypropylene or “Poly” Covering

Greenhouses are mainly frames covered with some sort of material that allows light to enter. The frame is the main structure, and determines the strength and shape the greenhouse will take. The covering is mostly for keeping the warm air inside and barring the cold air from entering. It is not load-bearing and is usually cheap and flexible.

Greenhouse polypropylene is the least expensive material we recommend for your greenhouse. “Poly” is graded by how many years it is expected to last in the full sun, and by how thick it is. Four-year, six mil (mm) thick poly is ideal for most greenhouses. This can be purchased in many widths and lengths from horticultural and agricultural supply companies, and of course just about anything can be ordered from online suppliers. There are also many types of rigid material that provide excellent insulation and yet still let light through. These are good for side walls and can be used to cover an entire greenhouse although they are much more expensive than flexible poly (also called greenhouse film by some suppliers).

One of the main considerations, when designing the greenhouse and choosing a covering, is rain. Rain water must be able to run off the top and sides of the greenhouse. For example, if a greenhouse is built with a flat roof and covered with flexible poly, that will be a disaster when it rains. Rain water is heavy! It weighs 2 pounds per quart. Once rainwater starts collecting in any hollow or depression in the poly, its weight will stretch the poly and create big sagging sections full of water that can’t escape. The important thing to remember is that all surfaces covered with poly must be angled so that water will flow off the surface and not collect on it. This is one of the main reasons that “hoop” greenhouses are so popular – the round shape sheds water very well. A-frame type greenhouses also work well to shed water.

Doors and Windows

Unattached Side Poly Rolled up in Summer

Besides allowing entrance to the greenhouse, doors and other openings in the greenhouse are crucial for allowing heat to escape. Greenhouses are very efficient at retaining heat while the sun is shining. The temperature in a fully closed greenhouse on a warm sunny day can reach 125°F (52°C), a temperature that is dangerous to both plants and people. Ideally, the greenhouse temperature will be kept under 100°F (38°C) and most plants grow best below 90°F (32°C). Doors and windows are the cheapest way to keep the greenhouse reasonably cool.

Another method for creating windows is to leave the side wall material unattached to the ground around the bottom of the greenhouse. Instead, cut the side wall material extra long and leave it lying loosely on the ground so that it can be rolled up and tied up during hot days. This allows air to enter and exit and helps remove excess heat. During the winter months, the excess side wall material can be held tightly to the ground with cinder blocks or other heavy material.

Simple Roof Flaps to Fold up or Down

Heat rises, so a way to let it out of the top of the greenhouse is always a good idea. Cutting simple roof flaps is one way to let heat out. Another way is automatic window openers that are set to open windows at a specific temperature and close them when the temperature drops. These do not require electricity but work on the principle of expansion and contraction of certain materials as they heat and cool. As the material expands it pushes the window open, and as it contracts it allows the window to close. Of course, you can manually open and close windows as well, but whenever it is possible to automate something in the greenhouse, you will find that it is helpful to do so.


All greenhouses need water for the plants. It can be from a hose, or you can easily run some PVC pipe into the greenhouse. Working with irrigation parts may seem daunting, but it is actually very simple and straightforward. All the parts are available at home supply stores and all you do is glue them together.


Greenhouses are heated by the sun any day it is shining and even when it is cloudy. However, a cold and cloudy day may not allow for enough heat to be generated to keep the greenhouse as warm as you would like. Nights are the bigger problem since inside a greenhouse the temperature will drop to within a couple of degrees of the outside temperature a few hours after dark. That may be sufficient for areas where the nights never get below 30°F (-1°C), but for most people, some greenhouse heating is worth considering. Both electric and propane/natural gas greenhouse heaters are available to do the job. Due to the high humidity, the sunshine, and temperature swings inside a greenhouse, we have found it best to use heaters intended for greenhouses because they hold up better.

Some Optional Goodies for the Greenhouse

Over time greenhouses tend to be improved upon as the people who use them figure out what is important to them. You can start growing hibiscus in the basic greenhouse described above. It provides for warmth and water and that is what it is all about! But below are some of the goodies you may want to add as you work with your greenhouse.

Wooden Tabletop on Cinder Blocks
With Drip Water System

Tables for Plants:

Tables are great – they raise the plants to a warmer air zone, keep them out of water runoff with the potential for spreading disease, and make it much easier for the normal person to work on the plants without having to stoop or bend over all the time. Tables can be made yourself. Make table tops out of 2×4 wood frames with 1×6 wood slats, and use cinder blocks for the table legs. Plastic waterproof tables are available from many sources as well.

Drip System with Timer:

Nothing frees up the plant lover like a drip system operated by a timer. This is by far the best way to water hibiscus so that the watering is regular and uniform and does not flood the pots. Try it, you’ll like it!

Wall Fans:

One of the best ways to maintain air flow through a greenhouse during warm weather is to install one or more big box fans into one of the walls of the greenhouse. These blowouts, not in, and the pressure they create draws fresh air in from the windows and doors that are left open.

Horizontal Air Fans

Horizontal Air Fans:

These are installed high up in the greenhouse and are intended to keep a gentle current of air circulating inside the greenhouse. This helps prevent fungal diseases and also mixes the air so that the greenhouse does not end up with hot and cold layers of air during the night.

Evaporative Cooler:

Often installed at the same time as the Wall Fan, the evaporative cooling system is built into the wall opposite the fan. It consists of water dripping down special material that is collected in a gutter and recirculated. When the fan is on and the water dripping fresh air is drawn through the wet material where it is cooled 15-20 degrees. The fan draws this humid cooler air through the greenhouse and out the opposite side. This “fan and pad” system will turn a 105°F (41°C) day into an 85°F (29°C) day inside the greenhouse – a great improvement in summertime heat!

Roll up Side Walls:

Available in both powered and manual versions, these walls can be rolled up during hot days and lowered at night where they fit snuggly into a ground level track to prevent air leakage.

Grow Lights:

Grow lights are not a real necessity for most parts of the world where hibiscus are grown. However, if you live in the far north or where clouds obscure the sun much of the time, adding HID or the new LED type grow lights to the greenhouse will give your hibiscus a boost when they need it most.

Insect Netting over Doors and Windows:

One of the easiest ways to control insects is to exclude them from the greenhouse with insect netting. There are now special net cloths that have holes small enough to keep out almost every known pest, including thrips which are very skinny.

Electronic Controls:

The irrigation timer is the simplest example of an electronic control. However, fancier ones can also control the heater, the fan, the pad cooling system, and any doors, windows or walls that are powered to raise and lower. In fact, electronic controls can control anything that runs on electricity, either by timers or by sensing conditions such as temperature.

Tropical Hibiscus ‘Acapulco Gold’ Blooming in a Greenhouse

The topic of greenhouses is a huge one. We are not able to cover more than the basics in this article.

Tropical Hibiscus: Wintering

For hibiscus lovers in the northern states, winter comes early, and so does the time to start figuring out how best to protect our hibiscus plants through the cold months. The most important consideration for tropical plants like hibiscus is staying warm in winter. Heat is more important than light or anything else, so let’s take a look at some good ways to provide heat to hibiscus in winter.

First and Foremost ~ Hygiene

First, before you do any moving, thoroughly wash your hibiscus. It is best to wash them several times before moving them inside, to make sure no stray pests have hopped onto them. Moving hibiscus is stressful to the plants, and any stress makes it harder for hibiscus to fight off pest attacks. Plus, indoor environments are cozy and wonderful for certain pests, like the obnoxious spider mite. So wash, wash, wash your plants to make sure you leave all pests outside. Spray every plant thoroughly with a strong spray of water, all sides of every leaf, stem, and branch. You don’t need soap or anything else, just water and lots of it. Wash your plants once or twice a week for 2-3 weeks before moving your plants inside. Then on the last washing, add horticultural oil to your water. It’s easiest to just pop a hose-end spray bottle onto your hose. Spray the plants heavily and thoroughly with the horticultural oil and water, then move them inside as soon as they dry on the last washing day.

Second ~ Don’t Stop Fertilizing!

If you stop fertilizing your hibiscus over the winter, they will go more deeply into dormancy and decline, and it will be much slower and more difficult to wake them up in the spring. It is very important to keep fertilizing through the winter months. If you use a Special-Blend Fertilizer, you will naturally water less in the winter, so you will naturally also use less fertilizer, which is perfect for your hibiscus. If you use a timed-release fertilizer, it will release more slowly in colder weather because the release rate is controlled by temperature. Your hibiscus is less actively growing and metabolizing in the winter, so they need less fertilizer, but they do need some fertilizer all winter long.

Overwintering in Cold Climates

Move them into the House

The place where hibiscus can stay warm without any extra cost is in your house. Although hibiscus is considered outdoor plants in the United States, in many parts of the world they are very popular houseplants, except for 2-3 months during summer when the pots may be set outdoors. Indoor hibiscus makes attractive, green houseplants. They help clean the air trapped inside in winter and give off extra oxygen. The greenery provides a wonderful backdrop to the drab and dreary weather of winter in many locations. And, every now and then, one of the hibiscus plants will bloom, providing a special indoor splash of color and beauty for that day.

Unless you live in Canada or northern Europe, you may not be accustomed to having hibiscus as houseplants, but they are easy to grow and quite suitable for indoor use. In the far north or any place where temperatures regularly fall below freezing during winter nights, tropical hibiscus will perish if left outdoors. Bringing them inside the house is an easy solution to overwintering them, but how best to do it?

The other main problem with placing hibiscus inside the house is finding space where there is adequate light. The closer to windows, the better for this purpose. But remember, hibiscus need warmth even more than they need light. So even if you only have room well away from windows, the hibiscus will do better there than if left outside or in an unheated garage. People have reported to us that directing just a little extra light to hibiscus in winter helps them stay green and healthy. A lamp placed nearby will help tremendously in a warm but rather dark area. What matters for hibiscus is the total amount of light they receive each day, so if the area tends to be dark you can leave a light on as much as 24 hours a day to help the hibiscus get what they need.
One of the potential problems is the size of the plants. Small hibiscus plants can grow very large by the end of summer. The simple solution to this is also good for the hibiscus – prune them back. You can reduce their size by as much as 50 percent without damaging them. More typically we cut the stems back by about 30 percent, but hibiscus is quite adaptable and will accept even severe pruning. So go ahead and reduce them to the size you need for them to fit well inside the house. Just be careful to leave some new growth and several older leaves on the plant after the pruning. Since it is winter and light are low, the hibiscus will grow back slowly, and should not grow large enough by winter’s end to become a problem in their indoor location. The idea is for them to get a head start on growing back during the slow growing season of winter, and then to rapidly grow to bloom size once they are placed outdoors in spring or early summer.

Garage, Shed, or Utility Room

If moving your hibiscus into the house is just not for you, then the next best strategy is to look for another solid structure where they can be kept over the winter. A garage, storage shed utility room, or any other structure that keeps out cold wind and provides some protection against the winter weather can be made to work. Again, the goal is to provide as much warmth as possible and at least some light to keep the hibiscus going. A structure with windows that allows sunlight to enter is ideal because the light will heat up the interior during the day and also provide the light energy needed by the hibiscus.


Even inside a shelter, in some colder climates, night-time temperatures can drop well below freezing. If possible place a small heater in the structure for use on those cold nights. Even better is a heater with a thermostat that you set to go on at 40°F (4°C) or higher. Small space heaters equipped with thermostats are usually inexpensive, so this doesn’t have to be a large expense. If you can afford to keep the structure as high as 65°F (19°C) the hibiscus will thrive. But with energy costs these days that much heat may not be affordable. The idea is to find the highest temperature you can afford to maintain, then set the thermostat to that temperature. Even 35°F (2°C) will help the hibiscus a great deal compared to allowing the temperature to fall below freezing.

Buying or building a greenhouse is the ultimate way to protect your hibiscus over the winter. These are wonderful additions to a property, and a good one will provide all sorts of opportunities to enjoy hibiscus year round. Whether you build your own or order one from one of the many greenhouse companies, such structures allow for year round growth and fresh flowers if heated to at least 60°F (15°C) during the winter.

One benefit of greenhouses is that they trap the rays of the early morning sun and heat the inside of the greenhouse far more rapidly than the outside air warms up. The greenhouse also reaches a much higher temperature during the day than the outside air. For instance, on a cold sunny day in a warmer climate zone, the temperature outside might be 35°F (2°C) at dawn, 50°F (10°C) by noon, and peak at 60°F (15°C) briefly in the afternoon. Compare that to the greenhouse temperature that, if unheated at night, will also be 35°F (2°C) at dawn, but reach 50°F (10°C) by 10 AM, 75°F (24°C) by noon, and peak over 80°F (26°C) during the afternoon. Similarly, the temperatures drop again rapidly at night outside, but in the greenhouse remain warmer for many hours before eventually matching the outside temps shortly before sunrise. With a heated greenhouse, the same thing happens but in addition to the warmth of trapping the suns rays in daytime, you also help the plants by keeping the temperatures at night at 60°F (15°C) or at whatever you set the thermostat for.

In a cold climate where heating costs are very high, most hibiscus can survive if temperatures stay at or above 35°F (2°C), but warmer is better. If you can afford to keep your greenhouse at or above 40°F (5°C), it will be much better for hibiscus. Every few degrees of extra warmth will mean healthier and happier hibiscus, so find the level that you can afford. Also, consider the duration of the cold temperatures. Sustained cold temperatures that last for many hours and/or many days or weeks will do more damage to hibiscus than an occasional dip into low temperatures for a short amount of time.

The ability to trap heat inside a greenhouse is so good that on warm sunny days the temperature will rise too high – even over 100°F (38°C) on some days. You need to build your greenhouse with sufficient windows and doors so that you can allow heat to escape on sunny warm days by opening them to the outside air. The main downside to greenhouses is that they involve an investment of money and time to build. If you decide to make this investment, it will pay off in great fun and success with winter growing of hibiscus outdoors.

Get creative!

Hibiscus 'Hibiscus at Christmas'
Hibiscus Blooming Indoors at Christmas

Some hibiscus lovers use their office space to grow hibiscus during the winter months. Or perhaps a relative or friend has a suitable space where you can winter your hibiscus. Avoid using a space that is too far from where you normally spend time, because the hibiscus will need to be checked on at regular intervals, mainly for watering.

Overwintering in Warmer Climates

If you live in a warmer climate, where temperatures rarely fall below freezing, and when they do it is only for one or two nights before warming up again, then you may be able to winter your hibiscus outside by providing some simple protection measures. If your area has a history of having fewer than ten nights per year that fall into the high 20’s (-2°C) or above and no nights colder than that, you have the possibility of protecting your hibiscus outdoors.

One of the best ways to protect outdoor hibiscus that is planted in the ground is to mulch over the root zone and around the main stem of the plant. A thick layer of leaves or compost can help protect the roots and keep them from freezing at night. This goes only so far though. For more protection, wrap the entire hibiscus bush in heavy frost cloth. This can add several degrees of freeze protection for the plants. In addition, you can run outdoor Christmas lights up under the frost cloth. During cold nights the lights can be turned on and the small amount of heat they give off will add several more degrees of warmth under the frost cloth. We have seen hibiscus bushes treated this way survive winters where temperatures reached as low as the 25°F (-4°C). A fully exposed hibiscus is usually severely damaged or killed by nights in the mid-20s, but just this amount of protection will prevent most frost damage.

Potted hibiscus in areas with just a few light freezes can be protected in other ways too. The pots can be moved up next to the house which will add a few degrees of warmth for them. A south or west wall with sun exposure during the day is another good place to locate the pots. Placing hibiscus under solid overhangs or under trees with thick canopies that prevent heat from radiating out into space at night also offer cold night protection. Some people report successful protection by tipping their potted hibiscus over on their sides and covering them with tarps or frost cloth on cold nights. Running Christmas lights under the tarps would afford even more protection.

Surviving an Unexpected Freeze

If your hibiscus is caught outside and unprotected by a sudden nighttime freeze, you can take action during the night to save them. This is a bad situation to be in but does happen occasionally even in the mildest climates. It happened to us three winters ago, and we used this strategy to save our hibiscus. We keep a temperature sensor outside in the hibiscus garden that radios the temperature to an indoor display so we can monitor the temperatures the hibiscus experience. This sounds exotic, but it is actually a simple device that is widely available at garden centers, costs well under $50, and runs on batteries.

One night three winters ago, we watched in dismay as the temperature dropped to freezing, then below freezing and showed no signs of stabilizing. By midnight it had dropped to 27°F (-3°C) and there was no way to protect our in-the-ground hibiscus. We had heard that simply running sprinklers on tropical plants could protect them from a freeze, and we decided to try it since we were sure our hibiscus would not make it through this very cold night without serious damage. So we went outside and turned on all our sprinklers. Soon all the hibiscus were being sprayed by the pop-up sprinkler system that was originally installed to water the lawn. How could this help, you ask? Well, the water coming up out of the pipes below the ground is considerably warmer than freezing. As this relatively warm water fell on the hibiscus and coated them, it protected them with a blanket of warm water. However, it was so cold that night that the water began to freeze on the leaves! We watched in horror as more and more ice built up on the plants, certain that we would lose all our hibiscus. Our sprinkler idea certainly looked disastrous, but it turned out to be protective. The continuous spray of water kept the ice temperature right at 32°F (0°C) and prevented it from dropping any lower. At 32°F (0°C) for only a few nighttime hours, the sap inside the hibiscus didn’t freeze. I left the sprinklers going until the air temperature rose above freezing the next morning and the ice melted off the hibiscus. Yes, we had a wet mess in the garden, and yes we wasted some water, but most of our hibiscus only sustained minor damage from that night and grew back the following summer as if they had never been through a hard freeze. We do not recommend this technique except in an emergency! But if you are ever faced with an unexpected hard freeze and unprotected hibiscus, a spray of water from sprinklers or hose will help keep the sap from freezing and prevent serious damage or death.

Older is Better

Tropical hibiscus can be grown and kept safe through winter, even in areas where freezing weather occurs. Remember, the main principle is to provide them with as much warmth as you can along with as much light as is practical in the warm area you place them in. The older the plants are the tougher they are in winter. We don’t worry at all about our 10-year-old and older hibiscus. Their thick woody main trunk and stems are not much affected by minor frosts and freezes and they are able to grow new shoots to replace any damaged ones each summer. The biggest challenge is with hibiscus experiencing their first winter. For these plants, we recommend an indoor, warm location whenever possible. If you provide the warmth, they will repay you with much beauty and enjoyment for years to come!

A Preliminary Analysis of the Botany, Zoology, and Mineralogy of the Voynich Manuscript

by Arthur O. Tucker, Rexford H.  Talbert

HerbalGram. 2013; American Botanical Council 

ONLINE NOTE: There are numerous usages of the Voynich Typeface/Font throughout this feature. Due to limitations in the online HTML coding, these are not present. Please refer to the printed or page-flip versions of HerbalGram

In addition, you can view a PDF of the article here. 


In 1912, Wilfrid M. Voynich, a Polish-born book collector living in London, discovered a curious manuscript in Italy. This manuscript, written in an obscure language or, perhaps, code, is now housed at the Beinecke Rare Book and Manuscript Library at Yale University,1 which acquired it in 1969. Since 1912, this manuscript has elicited enormous interest, resulting in books and Internet sites with no sound resolution on the manuscripts origin. Even the US National Security Agency has taken an interest in its cryptic contents, and doctoral theses have been written on attempts to decipher the language of the Voynich Manuscript (hereinafter abbreviated Ms.). With such voluminous published information, its history can be easily found elsewhere and need not be repeated here ad nauseum.1-5 However, what appears to be a reasonably reliable introduction for the novice is provided at Wikipedia.6

Information is continually updated on the website of René Zandbergen,7 a long-term researcher of the Voynich Ms., and, along with Gabriel Landini, PhD, one of the developers of the European Voynich Alphabet (EVA) used to transcribe the strange alphabet or syllabary in the Voynich Ms. As Zandbergen relates, past researchers primarily have proposed — because the Voynich Ms. was discovered in Italy — that this is a European manuscript, but some also have proposed Asian and North American origins. As such, almost every language, from Welsh to Chinese, has been suspected of being hidden in the text. Of course, aliens also have been implicated in the most bizarre theories. These theories with no solid evidence have clouded the whole field of study, and many scholars consider research into the Voynich Ms. to be academic suicide. Recently, however, Marcelo Montemurro, PhD, and Damián Zanette, PhD, researchers at the University of Manchester and Centro Atómico Bariloche e Instituto Balseiro, have used information theory to prove that the Voynich Ms. is compatible with a real language sequence.8

The Voynich Ms. is numbered with Arabic numerals in an ink and penmanship different from the works text portions. The pages are in pairs (“folios”), ordered with the number on the facing page on the right as recto, the reverse unnumbered on the left as verso (thus folios 1r, 1v, 2r, 2v, etc. to 116v). Fourteen folios are missing (12, 59, 60, 61, 62, 63, 64, 74, 91, 92, 97, 98, 109, and 110). By convention of Voynich researchers, the manuscript includes the following:

“Herbal pages” or a “botanical section” (pages with a single type of plant);

“Pharma pages” or a “pharmaceutical section” (pages with multiple plants and apothecary jars, sometimes termed “maiolica”);

“Astrological pages” (circular volvelles with nymphs, folios 70v2-73v);

“Astronomical pages” (other circular designs, folios 67rl-70r2, etc.);

“Balneological pages” or “biological section” (nymphs, baths, plumbing, folios 75r-84v);

Magic Circle page” (folio 57v);

“Fertilization/Seed page” (folio 86v); and a

“Michiton Olababas page” (folio 116v).

Our Introduction to the Voynich Manuscript, Backgrounds, and Pattern of Investigation

While we had known of the existence of the Voynich Ms., we, like so many others, probably dismissed it as a fantastic, elaborate hoax. Scattered, intersecting evidence may trace it back to ca. 1576-1612 to the court of Rudolf II (1552-1612) in Austria.1-7 Any origin prior to this time is strictly conjecture, but such spurious claims have channelized scholars thinking and have not been particularly fruitful. We had to face the facts that (so far) there was no clear, solid chain of evidence of its existence prior to ca. 1576-1612.

Thus, with our varied backgrounds and viewpoints as a botanist and as an information technologist with a background in botany and chemistry, the authors of this HerbalGram article decided to look at the worlds plants without prejudice as to origin in order to identify the plants in the Voynich Ms. With the geographical origins of the plants in hand, we can then explore the history of each region prior to the appearance of the Voynich Ms. The authors of this article employ abductive reasoning, which consists of listing of all observations and then forming the best hypothesis. Abductive reasoning (rather than deductive reasoning normally practiced by scientists in applying the scientific method) is routinely used by physicians for patient diagnosis and by forensic scientists and jurors to determine if a crime has or has not been committed. In abductive reasoning, it is necessary to record all facts, even those that may seem irrelevant at the time. This is well illustrated by physicians who have misdiagnosed patients who were not fully forthcoming with all their symptoms because they interpreted some as trivial, unrelated, or unnecessary to share with the physician.

We were both immediately struck by the similarity of xiuhamolli/xiuhhamolli (soap plant) illustrated on folio 9r in the 1552 Codex Cruz-Badianus9-12 of Mexico (sometimes known as the “Aztec Herbal”) to the plant in the illustration on folio 1v of the Voynich Ms. Both depictions have a large, broad, gray-to-whitish basal woody caudices with ridged bark and a portrayal of broken coarse roots that resemble toenails. The plant in the Codex Cruz-Badianus is in both bud and flower with leaves that have a cuneate (wedge-shaped) base, while the plant in the Voynich Ms. has only one bud with leaves that have a cordate (heart-shaped) base. The illustration in the Codex Cruz-Badianus is accepted by numerous commentators9-12 as Ipomoea murucoides Roem. & Schult. (Convolvulaceae); the illustration in the Voynich Ms. is most certainly the closely related species I. arborescens (Humb. & Bonpl. ex Willd.) G. Don. However, the portrayals of both of these Mesoamerican species are so similar that they could have been drawn by the same artist or school of artists.

This possible indication of a New World origin set us down a path that diverges from most previous Voynich researchers. If our identifications of the plants, animals, and minerals are correct as originating in Mexico and nearby areas, then our abductive reasoning should be focused upon Nueva España (New Spain) from 1521 (the date of the Conquest) to ca. 1576 (the earliest possible date that the Voynich Ms. may have appeared in Europe with any documentation). If the Voynich Ms. is, as one reviewer of this article indicated, “an invention by somebody in, lets say Hungary, who invented it based on images of early printed books,” then this forger had to have intimate knowledge of the plants, animals, and minerals of Mexico and surrounding regions, in addition to its history, art, etc. Some of this knowledge, such as the distinction of Viola bicolor (Violaceae; which is not illustrated in earlier books to our knowledge) vs. V. tricolor, was clarified only in the 20th century. A forgery is certainly possible, but applying the principle of Occams Razor (which says that the hypothesis with the fewest assumptions should be selected), attention should be focused upon Nueva España between 1521 and ca. 1576, not Eurasia, Africa, South America, or Australia (or alien planets).


Names as keys to decipher lost languages

The most fruitful, logical approach to initially decipher ancient languages has been the identification of proper names. Thomas Young (1773-1829) and Jean-François Champollion (1790-1832) first decrypted Egyptian hieroglyphics with the names of pharaohs that were found in cartouches, coupled with a study of Coptic (the later Egyptian language that used primarily Greek script). The initial attempts by many researchers to decipher Sumerian, Babylonian, and Assyrian cuneiform were the names of kings, in conjunction with links to ancient Persian. Michael Ventris (1922-1956) and John Chadwick (1920-1998) initially deciphered Minoan Linear B as Mycenaean Greek by identifying cities on Crete and finding links of these names to ancient Greek. Heinrich Berlin (1915-1988) initially deciphered Mayan logograms by connecting “emblem glyphs” with cities and ruling dynasties or territories, which allowed the breakthroughs of Yuri Knorosov (1922-1999), coupled with a study of Mayan dialects. Michael Coe (b. 1929) and others later found the names of gods in logograms repeated in the Popol Vuh, the Mayan holy book.13

Plant, Animal, and Mineral Names in the Voynich Manuscript

None of the primary folios with plant illustrations (the so-called “herbal pages”) have a name that can be teased out (yet). However, of the approximately 179 plants or plant parts or minerals illustrated in the “Pharma pages,” about 152 are accompanied by names. We were initially drawn to plant No. 8 of the 16 plants on folio 100r; this is obviously a cactus pad or fruit, i.e.Opuntia spp., quite possibly Opuntia ficus-indica (L.) Mill. (Cactaceae) or a related species. Thus,   is quite easily transliterated as nashtli, a variant of nochtli, the Nahuatl (Aztec) name for the fruit of the prickly pear cactus or the cactus itself. Then we looked at plant No. 4 on folio 100r, which appears to be a pressed specimen of a young Yucca spp. or Agavespp., quite possibly Agave atrovirens Karw. ex Salm-Dyck (Agavaceae). Here  transliterates to maguoey, or maguey. These initial keys of proper names allowed us to uncover further names, and details are listed in the Appendix of this article.

Not many of the names beyond nochtli and a few others have correspondences in the nine manuscripts,14 which include portrayals and discussions of 16th century Mesoamerican plants, particularly Codex Cruz-Badianus of 1552,9-12 Hernández of ca. 1570-1577,15 and Sahagúns Florentine Codex of ca. 1545-1590.16 It should be remembered that Hernández and his associates took surveys from all over Mexico, and these works and their Nahuatl names are not monolilthic, i.e., representing only one ethnic group.12 Thus, it is useful to distinguish the four classes of Nahuatl plant names as outlined by Clayton, Guerrini, and de Ávila in the Codex Cruz-Badianus:12

primary folk-generic names that cannot at present be analysed [sic] but which are likely to have been known widely and to be present as cognates in the modern Nahua languages…

compound folk-generic names

folk-specific names, composed of a generic term plus a qualifying epithet (which may be compounded into the name), a class less likely to be widespread…

descriptive phrases, which may have been coined by Martin de la Cruz himself (see below) and which are least likely to have been shared widely and to have been preserved in contemporary languages….

Thus the Nahuatl nochtli and the Spanish loan-word maguey fit the primary ‘folk-generic names of Number 1 above, but the use of the Nahuatl tlacanoni ()
— “bat” or “paddle” — for Dioscorea remotiflora Kunth (Dioscoreaceae) in No. 28 on folio 99r, fits the descriptive phrase of Number 4.

Further attempts at identifying the plants and their Nahuatl names, when given, are presented in the Appendix. Many of the identifications still need refinement. Also, because we have been trained as botanists and horticulturists, not linguists, our feeble attempts at a syllabary/alphabet for the language in the Voynich Ms. must be interpreted merely as a key for future researchers, not a fait accompli. Much, much work remains to be done, and hypotheses will be advanced for years.

Minerals and Pigments in the Voynich Manuscript

In 2009, McCrone Associates, a consulting research laboratory hired by Yale University, filed a report on the pigments in the Voynich Ms. with analyses done by chemist Alfred Vendl, PhD. They found the following:17

Black ink = iron gall ink with potassium lead oxide, potassium hydrogen phosphate, syngenite, calcium sulfate, calcium carbonate, mercury compound (traces), titanium compound, tin compound (particle), bone black, gum binder

Green pigment = copper-organic complex, atacamite (possible to probable), calcium sulfate, calcium carbonate, tin and iron compounds, azurite and cuprite (traces), gum binder

Blue pigment = azurite, cuprite (minor)

Red-brown pigment = red ochre, lead oxide, potassium compounds, iron sulfide, palmierite

White pigment = proteinaceous, carbohydrate-starch (traces).

This analysis was more thorough than the analysis done on 16th-century maps from Mexico, which did not identify the chemical nature of the particles.18 These pigments found by McCrone Associates in the Voynich Ms. differ from those of European manuscripts.19,20 In particular, atacamite is primarily from the New World (it was named after the Atacama Desert in Chile), and the presence of this New World mineral in a European manuscript from prior to ca. 1576 would be extremely suspicious.

However, these analyses remind us that the artist for the Voynich Ms. had a very limited palette and thus one blue pigment was used for all the hues, tints, and shades of blue, i.e., colors from blue-to-purple, dark-to-light. Likewise, one red pigment was used for colors from red-to-coral, dark-to-light, etc.

Folio 102r includes a cubic (isometric) blue mineral (No. 4) resembling a blue bouillon cube.  This might be boleite (KPb26Ag9Cu24Cl62(OH)48); the morphology of the primitive drawing certainly matches very closely. The only sources for large crystals of this quality and quantity are three closely related mines in Baja California, Mexico, principally the mine at Santa Rosale (El Boleo).21,22 These crystals, 2-8 mm on the side, typically occur embedded in atacamite. Copper compounds have been used historically to treat pulmonary and skin diseases and parasitic infections (e.g., shistosomiasis and bilharzia).23

The presence of five drop-like circles on the surface of this blue cube alludes to the Aztec logogram for water, atl, 9-12,16 and the name accompanying this, , we transliterate as atlaan, or atlan, “in or under the water.” Some minerals, e.g., tin (amochitl) and lead (temetstli), in the Florentine Codex16 also are illustrated with the atl logogram in allusion to the color of mist and foam. The translation of the accompanying text might tell us whether this blue cube and its name are referring to a mineral, a watery color, water itself, a technique of preparation, or even a calendar date.

Artistic Style: Emphasis of Plant Parts and So-Called Grafted Plants

The senior author of this article taught Horticultural Plant Materials at Delaware State University (DSU) for 36 years. Students had to learn the scientific name, the common name, a field characteristic, and uses of major horticultural plants ranging from significant conifers to houseplants (within one semester!). The class involved frequent field trips to collect living specimens. The students would inevitably gravitate to a type of plant illustration that is depicted in the Voynich Ms. For example, when they encountered birds nest spruce (Picea abies (L.) H. Karst. ‘Nidiformis, Pinaceae) in every class that was taught, one student would inevitably remark that the tips of the hooked needles of this conifer resembled Velcro®. The students would then start calling the birds nest spruce the “Velcro plant” and illustrate it in their notebooks with a circular birds nest outline and needles that were far out of proportion with the rest of the plant (a 0.5 inch needle was portrayed as a colossal one foot grafted onto three-foot plant). That is to say, the students omitted insignificant parts and enlarged important portions accordingly, often seemingly grafting them together. From a diversity of hundreds of students from various ages and ethnic backgrounds at DSU, this proved to be a common human pattern for notation and memorization, at least among university students in 20th century North America.

Thus, on folio 33v of the Voynich Ms., the illustration matches Psacalium peltigerum (B. L. Rob. & Seaton) Rydb. (Asteraceae) in botanical characters except for the size of the flowers. This may allude to the importance of the flowers, either for identification or use.

Also, following the same avenue of thought, in the case of the so-called “grafted” plants, e.g., Manihot rubricaulis I. M. Johnst. (Euphorbiaceae) on folio 93v, the artist may have merely left out the unimportant parts to condense the drawing to the limits of the paper size. This type of illustration also occurs in Hernández,15 e.g., tecpatli  (unknown, perhaps a Smallanthus spp., Asteraceae), teptepehoila capitzxochitl (unknown, probably an Ipomoea sp., Convolvulaceae) and tlalmatzalin hocxotzincensi (Brazoria arenaria Lundell, Lamiaceae), and uses the same sort of artistic device to compress a large plant into a small illustration. However, in Hernández, the cut portion is skillfully hidden from view, facing the back of the page. For chimalatl peruina (Helianthus annuus L., Asteraceae) in Hernandez, the top and bottom are shown side-by-side rather than attached.

Plants, Language, and Other Evidence of a Post-Conquest Central American Origin

The plants, animals, and minerals identified so far are primarily distributed from Texas, west to California, and south to Nicaragua, indicating a botanic garden somewhere in central Mexico.

Sources of Calligraphy in the Voynich Ms.

In 1821, Sequoyah (George Gist) created the Cherokee syllabary by modifying letters from Latin, Greek, and Cyrillic that he had encountered. Following this example, what was the inspiration for the calligraphy in the Voynich Ms.? Focusing upon the four most unique symbols ( ) in the Voynich Ms. and perusing documents from Nueva España 1521-ca. 1576, only one document reveals some calligraphy that might have served as inspiration for the Voynich Ms.: the Codex Osuna.24 In the Codex Osuna, there consistently is a broken version of “tl” in the Nahuatl that matches the same symbol “” in the Voynich Ms., and on folio 12v of the Codex Osuna, there is an identical version of “” on the lower left. Throughout the Codex Osuna (e.g., folio 37v), the “s” in the Nahuatl is often written as a large, conspicuous, backward version of that from the Voynich Ms. “”. On folios 13v and 14r of the Codex Osuna, the florid Spanish signatures have several inspirations for the “” in the Voynich Ms. On folio 39r of the Codex Osuna, the “z” is written in a very similar manner to the “” in the Voynich Ms.

The Codex Osuna24 was written between 1563-1566 in Mexico City and actually consists of seven books; it is not a codex in the strict definition. According to the Biblioteca Nacional, Madrid (Control No. biam00000085605), where it is listed as Pintura del gobernador, alcades y regidones de México, the Codex Osuna was:

A 16th century pictographic manuscript, written in Mexico. It contains the declarations of the accused and the eye witnesses made in New Spain by Jerónimo de Valderrama, by order of Philip II between 1563-1566, to investigate the charges presented against the Viceroy, Luis de Velasco, and the other Spanish authorities that participated in the government of said Viceroy. These people and their testimonies are represented by pictographs, followed by an explanation in the Nahuatl and Castilian languages, as the scribes translated the declarations of the Indians by means of interpreters or Nahuatlatos.

The Codex Osuna was donated in 1883 to the Biblioteca Nacional by the estate of Don Mariano Téllez-Girón y Beaufort-Spontin (1814-1882), 12th Duke of Osuna and 15th Duke of the Infantado.

The use of “tl” and “chi” endings places this dialect of Nahuatl in central or northern Mexico.25,26 The use of Classic Nahuatl, Mixtec, and Spanish loan-words for some plant names (see Appendix) also indicates an origin in central Mexico.

Other Indications of a 16th Century Mexican Origin

A number of other features of the Voynich Ms. also point to a Mesoamerican origin. For example, a “bird glyph” (folio 1r) as a paragraph marker is not known by the authors of this paper to exist in European manuscripts but as common in Post-Conquest Mexican manuscripts, e.g., the Codex Osuna24 and the Codex Mendoza27 (among many others).

A volcano is pictured on the top left side of folio 86v, within the crease. Mexico has roughly 43 active or extinct volcanoes, most centered near Mexico City. The most famous in recent centuries has been Popocatepetl in Morelos, southeast of Mexico City, a World Heritage Site of 16th century monasteries.

Animals in the Voynich Ms.

The fish illustrated on folio 70r are most definitely the alligator gar [Atractosteus spatula (Lacepède, 1803)]. This fish is very distinctive because of its pointed snout, length/width ratio, prominent interlocking scales (ganoid scales), and the “primitive”shape and distribution of the rear fins. The alligator gar is found only in North America.28 The Nahuatl name accompanying this illustration, otolal, transliterated to atlacaaca, means someone who is a fishing folk (atlaca, “fishing folk” + aca, “someone”). Curiously, there is an addition with this illustration of what seems to be “Mars” (French for March, perhaps?) in darker ink and different handwriting.

The dark-red bull illustrated on folio 71v is the Retinta breed of cattle (Bos taurus taurus Linnaeus, 1758), while the pale red is an Andalusian Red. Both of these types of cattle are notable for their upward curved antlers. The Spanish introduced Andalusian, Corriente, and Retinta cattle to North America as early as 1493 with Ponce de León in Florida. Cortés introduced cattle to Mexico some 30 years later. These breeds were chosen for their ability to survive the long sea voyage and later to endure grazing on just minimal “scrub lands.” Descendants of these cattle in North America, albeit with later interbreeding with dairy cattle, are Texas Longhorn cattle and Florida Cracker/Scrub/Pineywoods cattle.29 Curiously, on the illustration in the Voynich Ms., there is an addition in a darker, different ink and handwriting that seems to read “Ma.”

The crustaceans illustrated on folio 71v match the morphology of the Mexican crayfish, Cambarellus montezumae (Saussure, 1857). Acocil (from the Nahuatl cuitzilli) are found in a broad section across Mexico.28

The cat illustrated on folio 72r is the ocelot [Leopardus pardalis (Linnaeus, 1758)]. The stripes across the face, the rounded ears, and the gray spotting (illustrated with the blue pigment) are all characteristic of this cat. This species ranges from Texas to Argentina.28 Oddly, “angst” is written in a darker ink and different handwriting.

The sheep on folios 70v and 71r are bighorn sheep (Ovis canadensis Shaw, 1804). The hooves (two-cleft and hollow to clasp rocks) indicate that this might be the desert bighorn sheep (O. canadensis mexicana Merriam, 1901), which are found in deserts in southwestern North America and across Mexico.28 What seems to be the word “abime” (French for chasm or abyss) is attached to this illustration in a different handwriting and a darker ink.

A black Gulf Coast jaguarundi [Puma yagouaroundi cacomitli (Berlandier, 1859)] is portrayed on folio 73 (with what appears to be “noūba,” French for spree, written over the original writing with a darker, different ink). This cat, which has brown and black phases, is very distinctive in profile with a flatter face than most cats; the overall aspect of the face almost resembles a monkey. The tail is also notable, very long and particularly bushy at the base.

Additional tiny animals apparently are used as decorative elements and are difficult to identify: (1) a chameleon-like lizard (quite possibly inspired by the Texas horned lizard, Phrynosoma cornutum [Harlan 1825]) nibbling a leaf on folio 25v, (2) two caecilians [wormlike amphibians, probably inspired by Dermophis mexicanus (Duméril & Bibron, 1841)] in the roots of the plant on folio 49r, and (3) five animals at the bottom of folio 79v.

Other Evidence of Mexican Origin: The Influence of the Catholic Church

Besides Spanish loan-words, other indications of the European influence on Post-Conquest Mexico are the so-called “maiorica” or pharmaceutical containers in the “Pharma pages.” The sharp edges, filgree, lack of painted decoration, and general design allude to inspiration by metal objects, not ceramic or glass. The immediate suggestions for inspiration were the ciboria and oil stocks of 16th century Spanish Catholic church ceremonies. The former consists of a capped chalice, often on a highly ornamented stand, which stores the Eucharist. The latter consists of a cylindrical case comprising three compartments that screw into each other and hold the holy oils. Using these holy objects as designs for pharmaceutical containers would have been a mockery of the religion forced upon the conquered natives and thus another reason for writing in code. A ciborium also appears on folio 67r of the Codex Aubin.30

Future Avenues for Research

The Aztec elite were highly educated and hygienic. Cortéz reported libraries, called amoxcalli (Nahuatl for book house), complete with librarians and scribes. The Spanish conquistadors, along with the office of the Holy Inquisition burnt them all because of their “superstitious idolatry” (translated words of Juan de Zumarraga, first Archbishop of Mexico).14

Axiomatically, the Spanish priests established schools for children of the Aztec elite, teaching them European writing methods, painting, and Latin. Probably one of the most famous products of these schools, the Codex Cruz-Badianus, was completed by two students educated at the College of Santa Cruz in Tlatelolco. It was written in Nahuatl by Martin de la Cruz — a native convert and practicing physician at the College of Santa Cruz — and translated into Latin by Juan Badiano, another native convert and student of the College. Two versions of this manuscript exist, the original Codex Cruz-Badianus, formerly in the Vatican, returned in 1990 by Pope Paul II to Mexico (now at the Biblioteca Nacional de Antropologie e Historia in Mexico City [F1219 B135 1940]), and a later copy at the Royal Library of Windsor Castle (RCIN970335).9-12

The Aztecs also were the first to establish comprehensive botanic gardens, which later inspired those in Europe. Gardens were in Tenochtitlan, Chapultepec, Ixtapalapa, el Peñon, and Texcoco, as well as more distant ones such as Huaztepec (Morelos). Some of these botanic gardens, such as Huaztepec, included water features for ritualistic bathing. Coupled with this was the use of the temezcalli, or sweatbaths.31,32 

Besides outright destruction of the libraries by Spanish invaders, much of this accumulated indigenous knowledge also was destroyed by diseases, both imported and endemic. According to epidemiologist Rodolfo Acuña-Soto and colleagues,33 the population collapse in 16th century Mexico — a period of one of the highest death rates in history — shows that not only were European diseases devastating, but an indigenous hemorrhagic fever also may have played a large role in the high mortality rate. On top of the smallpox epidemic of 1519-1520, when an estimated 5-8 million natives perished in Mexico, the epidemics of 1545 and 1576 were due primarily to cocoliztli (“pest” in Nahuatl). These latter epidemics occurred during moist years following devastating droughts, providing food for a surge of rodents, which eventually killed an additional estimated 7-17 million people in the highlands of Mexico, roughly 90% of the population.33 This pattern is similar to the sudden, severe epidemics of other zoonoses (diseases of animal origin that can be transmitted to humans).34 Thus, the author(s) and artist(s) (tlacuilo, the native painter-scribes) of the Voynich Ms. may have perished in one of these epidemics, along with the speakers of their particular dialect.

Questions in the following paragraphs are particularly pertinent to fully establish this as the work of a 16th century ticitl(Nahuatl for doctor or seer).35,36

Interpretation of the flora and languages of Mexico is a difficult task even today. Mexico is extremely diverse in both floristics and ethnic groups, with approximately 20,000 plants and at least 30 extant dialects of Nahuatl.12 We are confident that our attempts at a preliminary syllabary for the Voynich Ms. can be refined. What are the linguistic affinities of this dialect to extant dialects of Nahuatl? Is this dialect truly extinct?

A six- to eight-pointed star, especially in the latter folios of the Voynich Ms. (103r-116r, where it often is dotted with red in the center), is used as a paragraph marker. Is this reminiscent of the eight-pointed Mexica Sun Stone or Calendar Stone? On the top center of folio 82r, the eight-pointed star is quite strikingly similar to this stone. This stone was unearthed in 1790 at El Zócalo, Mexico City, and is now at the capitals National Museum of Anthropology. One interpretation of the face in the center of this stone is Tonatiuh, the Aztec deity of the sun. Another interpretation of the face is Tlatechutli, the Mexica sun or earth monster. An identical eight-pointed star also appears on folio 60 of the Codex Aubin.30

What is the influence of the sibyls in the murals at the Casa del Deán (Puebla) on the portrayal of the women in the Voynich Ms.? The Casa del Deán originally belonged to Don Tomás de la Plaza Goes, who was dean of Puebla from 1553 to 1589 and second in command to the bishop. The murals were executed by native artists, tlacuilo, whose names are unknown.  Undoubtedly, much was destroyed through the centuries, and only two restored rooms remain. In La Sala de las Sibilias, or Room of the Sibyls, female prophets from Greek mythology narrate the passion of Christ. The women in the murals at the Casa del Deán have short hair and European features, and the friezes include nude angels and satyrs.

How was the parchment, which may date to animals killed in the first half of the 15th century, used over a full century later for this manuscript?37 How did putative medieval German script on folio 166v (the so-called “Michiton Olababas page”) get integrated into this manuscript?  Was this a case of European parchment being repurposed?

Copal resins (most commonly used for incense) were often used as binders in Mesoamerican pigments.18,38 McCrone Associates supposedly documented the IR spectrum of the resin.17 Is this a copal resin from a Meso-American species, such as Protium copal (Schltdl. & Cham.) Engl., Hymenaea courbaril L. (Fabaceae), or Bursera bipinnata (Moç. & Sessé ex DC.) Engl. (Burseraceae)?

What was the chain of evidence from post-Conquest Mexico to the court of Rudolph II? The circuitous route of the Codex Mendoza is perhaps illustrative of the fact that materials did not always flow directly from New Spain (present-day Mexico) to Spain, and European materials were quite often used for writing (rather than the native amate paper, amatl in Nahuatl). The Codex Mendoza was created in Mexico City on European paper about 20 years (ca. 1541) after the Spanish conquest of Mexico for Charles V, Holy Roman Emperor and King of Spain. It was sent by ship to Spain, but the fleet was attacked by French corsairs (privateers), and the Codex, along with the other booty, was taken to France. From there it came into possession of André Thévet, cosmographer to Henry II of France. Thévet wrote his name in five places in the Codex, twice with the date of 1553. It was later sold to Richard Hakluyt around 1587 for 20 francs (Hakluyt was in France from 1583-1588 as secretary to Sir Edward Stafford, English Member of Parliament, courtier and diplomat to France during the time of Queen Elizabeth I). Sometime near 1616 it was passed to Samuel Purchas, then to his son, and then to John Selden. The Codex Mendoza has been held at the Bodleian Library at Oxford University since 1659, five years after Seldens death.27

Another question is the involvement of John Dee (1527-1608/1609), if any. Dee — a Welsh mathematician, astronomer, astrologer, occultist, navigator, imperialist, and consultant to Queen Elizabeth I — purchased an Aztec obsidian “shew-stone”(mirror) in Europe between 1527-1530 (this object was subsequently owned by Horace Walpole). Dee was in Paris in the 1550s, and a letter dated 1675 quoted Arthur Dee, son of John Dee, saying that he had seen his father spending much time over a book “all in hierolyphicks.” Dee also is suspected of being the sales agent to Rudolf II, ca. 1584-1588.2-5


We note that the style of the drawings in the Voynich Ms. is similar to 16th century codices from Mexico (e.g., Codex Cruz-Badianus). With this prompt, we have identified a total of 37 of the 303 plants illustrated in the Voynich Ms. (roughly 12.5% of the total), the six principal animals, and the single illustrated mineral. The primary geographical distribution of these materials, identified so far, is from Texas, west to California, south to Nicaragua, pointing to a botanic garden in central Mexico, quite possibly Huaztepec (Morelos). A search of surviving codices and manuscripts from Nueva España in the 16th century, reveals the calligraphy of the Voynich Ms. to be similar to the Codex Osuna (1563-1566, Mexico City). Loan-words for the plant and animal names have been identified from Classical Nahuatl, Spanish, Taino, and Mixtec. The main text, however, seems to be in an extinct dialect of Nahuatl from central Mexico, possibly Morelos or Puebla.

Appendix: Plants Identified to Date

Beyond the approximately 172 plants, plant parts, and minerals in the “pharma section,” the “herbal section” includes about 131 plants. In the following, we have indicated only identifications that immediately “jumped out” to us with seemingly sound identifications. We have many more putative identifications, but these still are questionable, so they have been reserved for later publication. Unless financing could be procured for a large-scale project with leading scholars in botany, linguistics, and anthropology, decades of research remain. After all, we indicate only 37 plant identifications in the following pages (and boleite mineral) from a total of roughly 303 taxa (a meager 12.5% approximation of the total). And the text, bathing practices, astrology/astronomy, chain of evidence, etc., also need explanation.

Throughout this HerbalGram article, nomenclature and plant distributions follow the United States Department of Agricultures GRIN taxonomic database,39 and/or The Plant List produced by the Missouri Botanical Garden and Royal Botanic Garden, Kew,40 and/or the Integrated Taxonomic System (ITIS),28 unless otherwise indicated. The plants are listed below, alphabetically by family.

Apiaceae (Carrot Family)

Probably the most phantasmagoric illustration in the Voynich Manuscript is the Eryngium species portrayed on folio 16v. The inflorescence is colored blue, the leaves red, and the rhizome ochre, but the features verge on a stylized appearance rather than the botanical accuracy of the Viola bicolor of folio 9v, immediately suggesting that more than one tlacuilo (painter, artist) was involved. This lack of technical attention makes identification beyond genus difficult, if not impossible. However, a guess might be E. heterophyllum Engelm.41 This species, native to Mexico, Arizona, New Mexico, Louisiana, and Texas, has similar blue inflorescences, blue involucral bracts (whorl of leaves subtending the inflorescence), and stout roots, and it also develops rosy coloring on the stems and basal leaves. However, E. heterophyllum has pinnately compound leaves (leaflets arranged on each side of a common petiole), not peltate (umbrella-shaped) leaves. This lack of specificity on the shape of the leaves also plagues identifications in the Codex Cruz-Badianus.12 Today, E. heterophyllum, Wrights eryngo or Mexican eryngo, is used to treat gallstones in Mexico and has been found in in vivo experiments to have a hypocholesteremic effect.42

Apocynaceae (Dogbane Family)

Plant No. 14 on folio 100r appears to be the fruit of an asclepiad, possibly the Mexican species Gonolobus chloranthusSchltdl. The name  transliterates to acamaaya, a variant of acamaya, “crab” or “crayfish,” and the fruit of G. chloranthus does have a resemblance to knobby, ridged crab claws. The tlallayoptli in Hernández,13 with a similar illustration of the fruit (but with smooth ribs), is nominally accepted as the related species G. erianthus Decne., or Calabaza silvestre. The roots of G. niger (Cav.) Schult. are used today in Mexico to treat gonorrhea.43

Araceae (Arum Family)

Plant No. 7 on folio 100r appears to be the leaf of an aroid, most likely the Mexican species Philodendron goeldii G. M. Barroso. The name  transliterates as macanol, which refers to the wooden sword, macana (a Taino word, called macuahuitl by some authorities for the Aztec version), studded with slices of razor-sharp obsidian.

Plant No. 2 on folio 100r also appears to be a vine of an aroid, ripped from a tree, most probably Philodendron mexicanumEngl. The name  transliterates as namaepi, which may incorporate a loan-word from Mixtec referring to soap, nama, which is a plant that produces soap.44

Author Deni Bown writes of the Araceae in general: “Most of the species of Araceae which are used internally for bronchial problems contain saponins, soap-like glycosides which increase the permeability of membranes to assist in the absorption of minerals but also irritate the mucous membranes and make it more effective to cough up phlegm and other unwanted substances in the lungs and bronchial passages.”45

Asparagaceae (the Asparagus Family, alternatively Agavaceae, the Agave Family)

Plant No. 4 on folio 100r appears to be a pressed specimen of a young Yucca species or Agave species. Here  transliterates to maguoey, or maguey, a name that entered Spanish from the Taino in the middle of the 16th century,46 rather than the Nahuatl metl. Thus, this may quite possibly be Agave atrovirens Karw. ex Salm-Dyck, which was a source for the beverages pulque, mescal, and tequila in 16th century Nueva España.47,48 Mayaguil was the female goddess associated with the maguey plant as outlined in the Codex Rios of 1547-1566:49

Rios 15 (20v) Eighth Trecena: Mayaguil (Mayahuel)

They feign that Mayaguil was a woman with four hundred breasts, and that the gods, on account of her fruitfulness, changed her into the Maguei (Maguey plant), which is the vine of that country, from which they make wine. She presided over these thirteen signs: but whoever chanced to be born on the first sign of the Herb (Grass), it proved unlucky to him; for they say that it was applied to the Tlamatzatzguex, who were a race of demons dwelling amongst them, who according to their account wandered through the air, from whom the ministers of their temples took their denomination. When this sign arrived, parents enjoined their children not to leave the house, lest any misfortune or unlucky accident should befall them. They believed that those who were born in Two Canes (Reed), which is the second sign, would be long lived, for they say that sign was applied to Heaven. They manufacture so many things from this plant called the Maguei, and it is so very useful in that country, that the Devil took occasion to induce them to believe that it was a god, and to worship and offer sacrifices to it.

Asteraceae (Daisy Family)

In 1944, the Rev. Hugh ONeill at Catholic University wrote that the plant illustrated on folio 93r is sunflower, Helianthus annuus L. He wrote that six botanists agreed with him,50 but, in spite of this, non-botanists disagreed. This is most certainly the sunflower, called chimalatl peruiana in Hernández.15 The difficulty of portraying an exceedingly tall annual is conveyed in Hernández by having cut stems side-by-side, but in the Voynich Ms. the features are deeply compressed, possibly confusing non-botanists, but perhaps more difficult is the admission that the Voynich Ms. may be post-1492 or possibly from the New World!

The plant illustrated on folio 13r is probably a Petasites sp. The closest match might be P. frigidus (L.) Fr. var. palmatus(Aiton) Cronquist, the western sweet-coltsfoot. This is native to North America, from Canada to California. Petasites spp. are used in salves or poultices as antiasthmatics, antispasmodics, and expectorants.51

The plant illustrated on folio 33v is likely Psacalium peltigerum (B. L. Rob. & Seaton) Rydb., possibly var. latilobumPippen.52,53 This is a fairly good match to this New World asterid genus as to its lobed peltate (umbrella-shaped) leaves, inflorescence, and fleshy subterranean tubers, except that the flowers are shown in larger size than reality, perhaps to emphasize the identification or use. Psacalium peltigerum is known from the Mexican states of Jalisco, Guadalajara, and Guerrero, but the variety Platilobum is restricted to Guerrero. Psacalium peltatum (Kunth) Cass. is used for genito-urinary tract/reproduction treatment and for rheumatism in Mexico.54

Boraginaceae (Borage Family, Alternatively Hydrophyllaceae, the Waterleaf Family)

The plant illustrated folio 56r is almost certainly Phacelia campanularia A. Gray, the California bluebell. The blue flowers, dentate (toothed) leaves, scorpioid cyme (inflorescence coiled at the apex), and overlapping leaf-like basal scales are all good matches. This species is native to California.

Brassicaceae (Mustard Family)

The plant illustrated on folio 90v is most probably Caulanthus heterophyllus (Nutt.) Payson, San Diego wild cabbage or San Diego jewelflower. The flowers of C. heterophyllus are four-petaled, white with a purple streak down the center, with four protruding, dark purple anthers. Leaves vary from dentate (toothed) to lobed. It is native to California and Baja California.

Cactaceae (Cactus Family)

Plant No. 8 on folio 100r is obviously a cactus pad or fruit, i.e.Opuntia spp., quite possibly Opuntia ficus-indica (L.) Mill. or a related species (e.g., O. megacantha Salm-Dyck or O. streptacantha Lem.).47 Thus,  quite easily is transliterated as nashtli, a variant of nochtli, the Nahuatl name for the fruit of the prickly pear cactus or the cactus itself (the pads are called nopalli). Opuntia ficus-indica is widely cultivated but apparently native to central Mexico. Nopalea cochenillifera (L.) Salm-Dyck also is cultivated widely for the insect that is the source for cochineal.55

Caryophyllaceae (Carnation Family)

The plant illustrated on folio 24r is probably a Silene sp., possibly S. menziesii Hook., Menzies catchfly. This grows natively from Alaska to California and New Mexico. The flowers are a good match, even showing the infection with the fungus Microbotryum violaceum (Pers.) G. Deml & Oberw., anther smut fungus, which turns the anthers purple. However, the leaves are shown as hastate (arrowhead-shaped), and S. menziesii has attenuate (gradually narrowing to the base) leaf bases. Is this another case of disparity of the leaves between reality and portrayal, or is there another Silene species that is closer to the illustration?

Convolvulaceae (Morning Glory Family)

As mentioned previously, the plant illustrated on folio 1v is Ipomoea arborescens (Humb. & Bonpl. ex Willd.) G. Don, found from northern to southern Mexico. It is overwhelmingly similar to the xiuhamolli/xiuhhamolli (soap plant) in the Codex Cruz-Badianus9-12 of Mexico from 1552. Both trees have a large, broad, gray-to-whitish basal woody caudex (base) with ridged bark, portrayed here with broken coarse roots that resemble toenails. The plant in the Codex Cruz-Badianus is in both bud and flower with leaves that have a cuneate (wedge-shaped) base, while the plant in the Voynich Ms., has only one bud with leaves that have a cordate (heart-shaped) base. The illustration in the Codex Cruz-Badianus is nominally accepted as I. murucoidesRoem. & Schult. by leading commentators.9-12

The plant illustrated on folio 32v is probably I. pubescens Lam., silky morning-glory. This vine is native to Arizona as well as New Mexico to Argentina. The blue flowers, deeply lobed leaves, and tuberous roots are all characteristic of silky morning-glory.

Species of Ipomoea are known for their resin glycosides and use in treating several conditions, such as diabetes, hypertension, dysentery, constipation, fatigue, arthritis, rheumatism, hydrocephaly, meningitis, kidney ailments, and inflammation.56-58 In addition, the arborescent Ipomoea species, I. murucoides and I. arborescens, are used in hair and skin care, especially the ashes, which are used to prepare soap.55,58 While the bases of both of the arborescent species are portrayed somewhat accurately, Clayton, Guerrini, and de Ávila12 state that, “The blue patch with small, white ovate glyphs at the base of the plant is the symbol for flowing water.” This may be related to the story relayed by Standley for I. arborescens:  “In Morelos there is a popular belief that the tree causes imbecility and other cerebral affections [sic], and for this it is necessary only to drink the water running at the foot of the trees.”55

Dioscoreaceae (Yam Family)

The vine illustrated as No. 28 on folio 99r is likely Dioscorea remotiflora Kunth, native from northern to southern Mexico. The large root is paddle- or bat-like, and the name attached to this illustration is , tlacanoni, Nahuatl for paddle or bat.

The vine illustrated on folio 17v may very well be Dioscorea composita Hemsl., barbasco, native from northern to southern Mexico. The root quite often is segmented as shown in the Voynich Ms. and is a major source of diosgenin, a hormone precursor.

The vine illustrated on folio 96v is almost certainly Dioscorea mexicana Scheidw., Mexican yam. This also is native from northern to southern Mexico. This is another source of diosgenin.

Euphorbiaceae (Spurge Family)

The plant illustrated on folio 6v is very likely a Cnidoscolus sp., either C. chayamansa McVaugh or C. aconitifolius (Mill.) I. M. Johnst. Both are called chaya and are widely cultivated from Mexico to Nicaragua. The characteristic leaves and spiny fruit are both good fits, but because of the variability in both species (especially cultivated selections), it is difficult to tell for sure from the crude illustration that is portrayed.59

The plant illustrated on folio 5v is most probably Jatropha cathartica Terán & Berland., jicamilla. The palmately dentate (toothed) leaves, red flowers, and tuberous roots are all good fits for the species. Its native habitats are from Texas to northern Mexico. As the scientific name implies, this is cathartic and poisonous.

The plant illustrated on folio 93v is most likely Manihot rubricaulis I. M. Johnst. from northern Mexico. This close relative to the cassava, M. esculenta Crantz, has thinner, more deeply lobed leaves. Manihot rubricaulis is illustrated in Hernández15 as chichimecapatli or yamanquipatlis (gentle or weak medicine).

Fabaceae (Bean Family)

Plant No. 11 on folio 88r is almost certainly Lupinus montanus Humb., Bonpl., & Kunth of Mexico and Central America. This lupine is noted to contain alkaloids.60 The name attached to this is , aguocacha, which we translate as watery calluses. The compound peltate leaves and soft, callus-like, nitrogen-fixing root nodules (knobs) on one side of the roots are typical of this species.

Grossulariaceae (Gooseberry Family)

The plant illustrated on folio 23r is probably Ribes malvaceum Sm., chaparral currant. This woody, stoloniferous shrub has purple-magenta flowers and palmately (arranged like a hand) lobed leaves and is endemic to California south to Baja Norte, Mexico.55

Lamiaceae (Mint Family)

The plant illustrated on folio 45v is very possibly Hyptis albida Kunth, hierba del burro. The gray leaves, blue flowers, and stout root all match the characteristics of the species. This shrub is native to Sonora and Chihuahua to San Luis Potosí, Guanajuato, and Guerrero. Standley55 relates that “the leaves are sometimes used for flavoring food. In Sinaloa they are employed as a remedy for ear-ache, and in Guerrero a decoction of the plant is used in fomentations to relieve rheumatic pains.”

The plant illustrated on folio 32r is most likely Ocimum campechianum Mill. (O. micranthum Willd.). This suffrutescent (low-shrubby) annual basil grows indigenously from Florida to Argentina; in Mexico it is found from Sinaloa to Tamaulipas, Yucatán, and Colima.55 The inflorescence and leaves are both good matches. Standley55 relates, “In El Salvador bunches of the leaves of this plant are put in the ears as a remedy for earache.”

Plant No. 5 on folio 100r has three flowers that match Salazaria mexicana Torr., or bladdersage.  This species also seems to match the description of tenamaznanapoloa (carrying triplets?) of Hernández15 (alias tenamazton or tlalamatl). This shrub, native from Utah to Mexico (Baja California, Chihuahua, and Coahuila), exhibits inflated bladder-like calyces that vary in color, depending upon maturity, from green to white to magenta, with a dark blue-and-white corolla emerging from it.55 We have transliterated the name accompanying these three flowers,  as noe, moe-choll-chi. The name choll-chi we translate as skull-owl (Spanish cholla plus Nahuatl root chi), and, indeed, the flowers do bear an uncanny resemblance to the white skull and black beak of the great horned owl (Bubo virginianus Gmelin 1788).

The plant on folio 45r most likely is Salvia cacaliifolia Benth., endemic to Mexico (Chiapas), Guatemala, and Honduras. The blue flowers in a tripartite inflorescence (branching in threes) with distantly dentate (toothed) deltoid-hastate (triangular-arrowhead-shaped) leaves are quite characteristic of this species.61

Marantaceae (Prayer Plant Family)

The plant illustrated on folio 42v is a crude representation of a Calathea spp., probably allied to C. loeseneri J. F. Macbr., which yields a blue dye. The crudeness of the illustration, coupled with inadequate surveys of the genus Calathea in Mexico, impede an easy identification at this time.

Menyanthaceae (Buckbean Family)

The obviously aquatic plant illustrated on folio 2v is undoubtedly Nymphoides aquatica (J. F. Gmel.) Kuntze, the so-called banana plant or banana lily. This is native to North America, from New Jersey to Texas.

Moraceae (Mulberry Family)

The plant illustrated on folio 36v is probably a Dorstenia sp., likely the variable D. contrajerva L., tusilla. The inflorescence is quite distinct and is genus-appropriate. Leaves for this species vary “in spirals, rosulate (in the form of a rosette) or spaced; lamina broadly ovate (egg-shaped) to cordiform (heart-shaped) to subhastate (tending towards arrowhead-shaped), pinnately (arranged on opposite sides of a petiole) to subpalmately (tending to be arranged as a hand) or subpedately (tending to be two-cleft), variously lobed to parted with three-to-eight lobes at each side or subentire (tending to have a smooth edge).”62

Passifloraceae (Passionflower Family)

The plant illustrated on folio 23v is definitely a Passiflora sp. of the subgenus Decaloba. This is primarily a New World genus (some species occur in Asia and Australia) and cannot be confused with any other genus. The paired petiolar glands in the upper third of the leaf, blue tints in the flower, and dentate (toothed) leaves that are deeply cordate (heart-shaped) seem to match only the variability of P. morifolia Mast. in Mart.,63 although the artist has made the leaves slightly more orbicular (round) than they normally occur in mature foliage (young plants such as root suckers sometimes exhibit orbicular, entire leaves in cultivation).

Penthoraceae (Ditch-Stonecrop Family)

The plant illustrated on folio 30v is easily identifiable as Penthorum sedoides L., the ditch stonecrop, a New World species that grows indigenously from Canada to Texas. The cymose inflorescence (convex flower cluster), dentate leaves, and stolons (trailing shoots) are characteristic of the species. The artist, though, apparently has illustrated this in very early bud (or glossed over the details of the flowers) because the prominent pistils emerge later, and are very obvious in fruit, often turning rosy.

Polemoniaceae (Phlox Family)

The plant illustrated on folio 4v is quite definitely a Cobaea sp., a New World genus. The best match is C. biaurita Standl., which is closely related to the cultivated C. scandens Cav., the cup and saucer vine. This vine is native to Chiapas, Mexico, and possesses acute (tapering to the apex, sides straight or nearly so) to acuminate (tapering to the apex, sides more-or-less pinched) leaflets and flowers that emerge cream-colored but later mature to purple.64,65

Ranunculaceae (Buttercup Family)

The plant illustrated on folio 95r is quite definitely an Actaea sp., probably the white-fruited Actaea rubra (Aiton) Willd. f. neglecta (Gillman) B. L. Rob. Actaea rubra is native to Eurasia, and in North America from Canada to New Mexico.66 As the common name baneberry indicates, this species is poisonous.

Urticaceae (Nettle Family)

As first postulated by the Rev. Hugh ONeill, the plant on folio 25r is clearly a member of the Urticaceae, or nettle family.50The best match, because of the dentate, lanceolate (lance-shaped) leaves and reddish inflorescences, seems to be Urtica chamaedryoides Pursh, commonly known as heart-leaf nettle. This is native in North America from Canada to Mexico (Sonora). Urtica and the closely related genus Urera also occur in the Codex Cruz-Badianus9-12  and Hernández.15

Valerianaceae (Valerian Family)

The plant illustrated on folio 65r is probably Valeriana albonervata B. L. Rob. The palmately or cleft-lobed leaves, inflorescence, and napiform (turnip-shaped) to fusiform (spindle-shaped), often forked taproots, are a good match. This is native to the Sierra Madre of Mexico.67

Violaceae (Violet Family)

The plant illustrated on folio 9v has been identified previously as Viola tricolor of Eurasia,68 but we claim that it is not this species. If the illustration in the Voynich Ms. is correct (and the illustration is actually quite decent), the terminal stipular lobes are linear (narrow and flat with parallel sides), as characteristic of the North American native V. bicolor Pursh (V. rafinesqueiGreene), not spatulate (spatula-shaped) as in V. tricolor. Also, the flowers of V. bicolor are uniformly cream to blue, while the flowers of V. tricolor usually have two purple upper petals, three cream-to-yellow lower petals. Viola bicolor, American field pansy, is native to the present-day United States from New Jersey to Texas, west to Arizona, although Russell mysteriously says “originally derived from Mexico” even though its center of diversity seems to be eastern Texas.69,70


Arthur O. Tucker, PhD, is emeritus professor and co-director of the Claude E. Phillips Herbarium at Delaware State University in Dover, an upper-medium-sized herbarium and the only functional herbarium at an historically Black college or university, graced with a few type specimens of Mexican plants collected by Ynes Mexia, Edward Palmer, et al.71 He has had a special interest in identifying plants from period illustrations utilizing flora and herbarium specimens, e.g., the Blue Bird Fresco at Knossos.72 Because of his expertise, he was hired by CPHST/PPQ/APHIS/USDA (Center for Plant Health Science Technology/Plant Protection & Quarantine) to identify botanicals imported to the United States and to construct a Lucid key.73The latter research was particularly challenging because these botanicals encompass parts of everything botanical  from fungi (though not truly botanical), to mosses and lichens, to gymnosperms and angiosperms that had been greatly modified (bleached and/or dyed, scented, and sometimes reconstructed into new botanicals)  collected in India, China, Southeast Asia, Australia, Brazil, etc. Dr. Tucker also has published widely on the systematics and chemistry of herbs in both scientific and popular journals and is the co-author of The Encyclopedia of Herbs (Timber Press, 2009), which attempts to summarize the latest scientific information on herbs of flavor and fragrance for the average reader.74

Rexford H. Talbert, a retired Senior Information Technology Research Scientist from the United States Department of Defense and the National Aeronautics and Space Administration, is an autodidact, writer, and lecturer in botany, plant taxonomy, and plant chemistry with a keen interest in ethnic plants.



The authors gratefully appreciate the discussion and proofing by Arthur O. Tucker, IV; Sharon S. Tucker, PhD; and Susan Yost, PhD.


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