Yam A: The Alata

by Green Deane

in Flour/Starch, Plants, Roots/Tubers/Corms, Vegetable, Vines

Dioscoria alata, yam whose root is most prized

The  Dioscorea Dilemma: Which ones are edible, and what parts?

One wouldn’t think wild yams would be hard to sort out. It only took me about a dozen years.

I’m not talking about anything related to the sweet potato. That’s the Ipomoea family. I’m talking about real yams, in the Dioscorea family. Like many imported plants into warm climates, the Dioscorea (Dye-os-KOH-ree-uh or in Greek thee-oh-skor-REE-uh) have become an invasive weed. And as you know, the motto here is eat the weeds. Let’s see if we can sort them out. There are three escaped yams locally. I call them Yam A, Yam B and Yam C.

The Root of the D. alata, Yam A grown in hard soil

The most common yam in the South is, unfortunately, probably the least edible, Yam B, the Dioscorea bulbifera — B for bulbifera (bul-BIFF-er-ra.)  It was first sent to Orlando in 1905 as a possible ornamental and food crop. The fellow who got the D. bulbifera concluded it was dangerous to Florida but didn’t eradicate while he had the chance. It has since escaped and become a scourge of the countryside. I have not personally proven its edibility. I have a separate article elsewhere on this site called “Yam B: The Bulbifera.”  Yam C is the Chinese Yam or the Cinnamon vine yam. It’s botanical name is Dioscorea polystachya (mistakenly called D. oppositifolia.) It is covered in a different article as well. Yam C: The Chinese. This article is about Yam A, Dioscorea Alata — A for Alata uh-LAY-tuh. It is also called the Winged Yam because its stem is very square.

D. alata, Yam A, under cultivation in soft soil

Yam A, or the winged yam, is also called the “water Yam” the “great yam” the “lesser yam,” and the “purple yam” among others.  It’s not born free anywhere in the world but is a product of cultivation that has escaped into the wild. Researchers think it was an intentional hybridizing of two wild yams by man some 8,000 years ago. So while Yam A, the D. alata, is found in the wild, it is not a wild yam.

Under cultivation, varieties of D. alata  are the most common yam in the world.  It has an underground root that can grow upwards of 7.5 feet long and a 136 pounds (the known record is 180 pounds.)  When cultivated it can grow long and uniform. In hard soil, or in old age, it can be lumpy and malformed. Young roots tend to be solid and straight, older roots tend to branch out. Boiling (or roasting) of the root makes it edible. It got to Africa from Asia around 1,500 B.C. and probably came to the Americas with slaves by the 1700s. By the 1950s D. alata was the most common Yam in the state. The D. bulbifera did not take over for a few more decades.

Above ground differences betwen Yam A, the Alata, and Yam B, the Bulbifera

At first glance Yam A, the D. alta, and Yam B, the D. bulbefera, look quite alike but they have several differences. D. alata’s leaf is an arrow-shaped heart (think arrow-Alata)  D. bulfiera is a ball-shaped heart (think ball-bulifera). The D. alata leaves grow in pairs particularly near the growing end of the vine where as young D. alatas can have one leaf instead of leaves in pairs, the D. bulbifera singly. The D. alata has a large, very square stem with edges tinged in purple, the D. bulbifera has a slight round green stem. The D. alata has bulbils that are dark brown with a variety of shapes, the D. bulbifera has bulbils that are lumpy round and tan (from Asia I think) or round and brown with tan pimples (from Africa I think). Incidentally, D. alata bulbils soaked 4 hours in water germinate three weeks faster than non-soaked bulbils.

The so-called Z-twist goes from our lower left to our upper right at eye-level

The D. alata, when climbing at eye level, twists from your lower left across the surface nearest you to your upper right, the so-called Z-twist. The D. bulbifera twists from your lower right across the surface nearest you to your upper left, the S-twist. I am beginning to think the way of the twist is the first sign of a prime edible yam. Ignore books that say a vine twists clockwise or counter clockwise if they don’t provide you the perspective of the viewer. Depending whether you are looking down or up the same twist can be called clockwise or counter clockwise. If you are looking down at a D. alata it looks to go counter clockwise. If you’re looking up at the D. alata it appears to go clockwise. I have two books that describe its twist in different directions because of the perspective.

Once you learn to tell the differences the D. alata  (as well as Yam C, the Chinese Yam) are fairly easy to spot among their prolific relative, the D. bulbifera. Yam A and Yam C (the Chinese Yam) leaves give them away even at a distance since they grow in pairs. The D. bulbifera has alternating single leaves so from a distance if you see single leaves like a series of steps in a stairs you know it’s not the one you want.  As for availability… along one bike trail I traverse, for one mile all the trees are draped with Yam B. But, there are three patches of Yam A. Yam C is in very isolated pockets.

D. alata’s air bulbils are NOT round and are NOT tan

While the D. Alta has a reputation for being buried very deep that has not been my experience. I usually find the large root within a few inches of the surface. When grown in soft soil the D. alata is long and tubular, when growing in hard soil it will be lumpy and distorted. Old roots can also be lumpy and banched. The largest I have found to date is 8.2 pounds after washing, and that is the norm. Young roots are best used like potatoes, older roots while edible have a different texture, can be fried after boiling or make a good flour. The vine usually puts on one tuber per season but can produce as many as three. Thus the older root can be lumpy but have a younger, well-formed root attached, as the top picture shows.

Sassycrafter and a 30-pound D. alata root

When under cultivation the D. alata is usually left to cure for a week after it is dug up, but that’s not necessary, and it will store for several months. The vine also go into a dormant period. Here in Florida that is about Christmas to St. Patrick’s Day. During that time the vines die back. If you want to dig them up during that time you should mark them earlier in the season. The U.S. Department of Agriculture reports the bulbils of the D. alata are edible cooked but not as palatable as the roots, and my friend, Maribou, has tried them. I, personally, have not gotten around to eating them. It’s on my list of plant things to do.

Dioscorea was named after Pedianos Dioscorides, Greek physician of the first century AD whose book on medicinal herbs Materia Medica, was a standard work until recent times. Alata means winged. Bulbifera means bearing bulbs. Polystachya, many stakes, or blossom spikes.

D. villosa roots are famine food and birth contol, best avoided

For the record, among the semi-edibles yams one might see are: Dioscorea villosa, (vill-LOE-suh) whose roots might be a famine food but with a price. This was the yam from which the first birth control pills were made. There has been some speculation that the Mayans suffered a loss of their maize crop and had to eat D. villosa, causing a fertility drop in their population they could not recover from. (It twines lower right to upper left, the S-twist.)   There are also native Florida yams, but they are rare and have no “bulbils” Dioscorea floridana and Dioscorea quarternata. The native plants are only infrequently seen in north and west Florida hammocks and flood plains. Villosa means shaggy; floridana, Florida; quarternata, four leaves from one place; polystachya many spikes. The word “yam” comes from a west African language and means “something to eat.”

Approximate yam nutrition per 100g: 103 calories; sugars (g)  23; Proteíns (g) 1; Fiber (g) 4; Vitamin B1 (mg) 112; Vitamin B2 (mg) 32; Vitamin C (mg) 17; Salt (mg) 9; Potássium (mg) 816; Cálcium (mg) 17; Phosphorus (mg) 55. It does not have any iron, fat, vitamin A, and no vitamin B3.

Green Deane’s Itemized” Plant Profile

IDENTIFICATION: Dioscorea alata:  Winged Yam. Large arrow-shaped leaves, opposite, stem with four definite sides, edges of the sides often tinged in purple. Stem climbs from lower left to upper right. Bulbils dark brown, round or cylinder, lumpy, mishapen. Underground root similar to a sweet potato in shape when grown is soft soil, lumpy and distorted when grown in hard soil. Can be up to 136 pounds.

TIME OF YEAR:  Fall, September to December. For two months the vine dies back making locating difficult.

ENVIRONMENT: Yams do well in sun or partial shade and prosper with ample rainfall. They require good drainage, and therefore, are often planted on mounds or ridges.

METHOD OF PREPARATION:  Underground roots only: Usually fresh young yam is peeled, cut up and boiled like a potato. Older yams can be pounded into a sticky elastic dough called pounded yam or yam fufu. To make a flour from the D. Alata root slice the underground tubers to a thickness of about quarter inch. Parboil the peeled slices. Dried them in the sun to reduce the moisture content. The dried slices are then ground to flour and sieved to make a uniform texture. Otherwise, the boiled yam can also be used like potatoes.   IF ANY YAM TASTES BITTER, DON’T EAT IT.

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{ 43 comments… read them below or add one }

1 Chris October 26, 2011 at 03:50

I have 2 different yam plants, D. rotundata (white yam) and D. cayenensis (African yellow yam.) I recently picked up some tubers that were labeled as Oriental Yams at a produce stand but they look nothing like the 2 others I grow nor do they look like the photos in this article.

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2 Green Deane October 26, 2011 at 04:43

Got a location on the rotation? Are you referring to roots, leaves, bulbils or all three and at what stage of growth? And, there are many cultivas… if you got it from a produce stand its probably safe…

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3 Rich November 17, 2011 at 09:00

Can you harvest part of the root so as not to kill the plant for future harvest?
Thank you for your time and knowledge.

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4 Green Deane November 17, 2011 at 09:44

Yes, in fact it often grows in separate sections adding them depending upon the season.

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5 Ryan Stallings December 29, 2011 at 23:25

Can the bulblets be planted to propagate it? A suggestion, in addition to ITEM-IZING plants, cover Propagation if there is time or in the written articles. If we can’t propagate the plants, we are done for in the long run…..thanks for all the great articles and vids.

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6 Green Deane December 30, 2011 at 07:05

Yes they can… hmmm… propagation never really came into it because weeds do it so well themselves. I can add it over time… I mean.. with nearly 500 articles and 1,000 species it takes time to make changes.

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7 Allen July 2, 2012 at 03:31

Hi! I’m Allen and i’m 15. I am very interested in self reliance and have found your videos and websites extremely helpful. Using your site I have made a yucca rope hammock, snares made with yucca, blackberry cobbler and jam. As I said before your website was extremely instrumental and is the only real wild Florida plant guide I could find. Thanks!

On another note…I would like to start cultivating some plants. I already have 8 blackberry bushes and 16 yuccas growing. I would like to expand and add something starchy. I live in Gainesville and have 5 acres of land…Could I have some of these yams on my property or somewhere in the vicinity? Thanks in advanced!

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8 Green Deane July 2, 2012 at 12:34

The short answer is yes, and I sent you a message about that.

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9 dew August 4, 2012 at 23:30

interesting research. comparisons of yams, particularly yam “a” or the d. alata, purple yam/winged yam

http://www.scribd.com/doc/34858900/Dioscorea-Alata-Flour

enjoy

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10 Mozartghost August 6, 2012 at 15:45

Some days it seems like everything edible is in Florida…

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11 Violet December 6, 2012 at 09:15

I’ll have to disagree with you. As someone who forages the Catskill Mountains and most of Vermont…. it seems like everything in Vermont and the Catskills is edible. :-)….oh, minus the snakes, bugs and poison ivy of course.

I mostly pick mushrooms….but love to forage for food. This site…. is my dream.. since I don’t know much about Florida plants in general…….yet.

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12 carol January 22, 2013 at 11:17

you have so much info to share do you have a ebook pdf that has your archive

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13 Green Deane January 28, 2013 at 13:59

working on one.

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14 Carol Tibbs April 9, 2013 at 13:43

Hello I was on your class in Cassadaga on Saturday, sure enjoyed the walk and learning about the good things to eat. Today i dug up the D. alata yam that has been growing on my fence for many years, altho it is dead and the vine no longer touches the ground, but i did see where it might have gone into the ground, dug there and found a nice root about the size of a regular sweet potato. Washed it off and took a little taste, it was surprisingly tender for being such an old plant, had no particular taste, and kinda sticky, i will try boiling it and see what it taste like than. I read as much as i could about it, could it be planted like a regular crop in the garden? and dug up each year? Third question how do you prepare a Cicada? As i am sure if their 17 year hibernation is over we will have our share in Florida also. Don’t really think i will eat any, i just love the little bugs and the way when you hold them by their tails their wings just go so fast they buzz.

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15 gaquiere Irene May 29, 2013 at 12:00

hi! since three year we are trying to grow the yams but we they always got frozen, could you please help us? thank you! we loved your clips.

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16 Adrienne June 4, 2013 at 12:27

These yam plants came from bulbils that resemble yam A. The stems are thicker and seem square. The vines climb as “Z” form. BUT the leaves are only single!! I had them ready to plant, but re-read your article, and now am ready to trash them. Are these some sort of cross-polinated hybrids?
Help!

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17 Green Deane June 4, 2013 at 17:01

Young winged yams vines start out with single leaves then later double up.

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18 Adrienne June 4, 2013 at 12:31

I forgot to mention that they came from the section of the garden that I had yam A growing, I picked off the bulbils myself in the winter, and a few of the bulbils have produced double-leaf vines.

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19 art smuth June 21, 2013 at 20:13

i have a plant that looks like this but has orange yellow flowers – are there any flowers on Dioscorea spp and if so what color are they?

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20 Green Deane June 23, 2013 at 19:00

Dioscorea so have flowers but they are small and irrelevant.

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21 Lynn June 28, 2013 at 15:24

Where can I get the seed for the D. alata to grow? I read on a website it is poisonous. You mention “When under cultivation the D. alata is usually left to cure for a week after it is dug up”, what do you mean by cure? I tried searching the web but they only provided wild yam, I believe that is the Yam C you mentioned above.

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22 Green Deane June 28, 2013 at 15:30

Usually one does not grow the yams from seed but rather from the air bulbils. Many root vegetables are left to sit out of the sun for a week after being dug up. Sweet potato are for example. Some yam’s have roots and air bulbils that are toxic. I have written about them extensively. I think you will find you answers in those three articles; Yam A, Yam B, Yam C. As for finding the air bulbils of Yam A, it depends on where you live.

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23 Jessica Wessels July 10, 2013 at 22:37

Hello Green Deane, Thank you so much for the great read. I would like to ask you a question regarding the Dioscorea batatas. I want to buy from a company that sells the vine and they claim “The wild yam has edible root tubers as well as tiny edible tubers on the vines in the fall.” And I take it from your article here that they are not in the Dioscorea alata. Could they perhaps be mistaken on their claim that the tiny tubers on the vines are edible? Also, I would like your opinion on the Dioscorea batatas if you have any please. :::Big Hugs:::

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24 Green Deane July 11, 2013 at 05:04

D. batatas is just another name for the plant on my site called Yam C.

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25 Toks Sho September 17, 2013 at 01:39

Hello,

I’m quite excited to see such extensive research into yam. Do you know if D. Alata will grow around Houston?

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26 Green Deane October 1, 2013 at 19:33

If the ground does not freeze it might.

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27 Brenda Zhao January 23, 2014 at 16:35

Hi, my name is Brenda.
Could you please give me some informations about where and how to buy this D. alata yam? Thank you!

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28 Green Deane January 23, 2014 at 20:20

It is the yam you can buy in Malaysian or Hispanic markets. It is just the escaped version of the cultivated one.

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29 Brenda Zhao January 23, 2014 at 21:21

Thank you!

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30 Kathy S February 2, 2014 at 12:30

I purchased a big wet bob of d. Alata at the farmers market yesterday. Im letting it dry a bit and will try cooking in a few days. I’d also like to propagate from this big root. Do you think I can start new plants from the toes, rather than the bulbils?

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31 Green Deane February 2, 2014 at 17:10

Yes, you can. Plant them in good soil around tax day.

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32 Kathy S June 4, 2014 at 15:36

Just reporting back that my little purple toes are now beautiful purple-stemmed vines. The yam was rather bland when we ate it, but a beautiful color.

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33 linsu wood February 19, 2014 at 20:18

I dug up the winged yam that I planted from the air potatoes and when I peeled it there was some pink coloring on it. Also after I boiled it the water had a pinkish tint. Bad yam? or normal?

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34 Vic Cherikoff March 7, 2014 at 14:46

Hi Deane,

I have several D.alata vines that grow every year in my vegetable patch. I have never had flowers or bulbils on them and so have not harvested the tubers. The original tubers were brought back from our tropical north where I found the plant growing in a rainforest vine thicket. Do you know if an I modify the nutrition of the plant to induce bulbil formation or flowering?

Cheers,
Vic

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35 Kim March 16, 2014 at 14:30

I just dug up 2 beautiful D.alata tubers. Can’t wait to try them. Thanks for all your education!! Here’s the link for a pic of my yam – https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-frc1/t1/10014654_10202964353730455_1228188286_n.jpg

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36 Green Deane March 16, 2014 at 16:21

Where are you that you dug it up this time of year?

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37 Matt April 27, 2014 at 16:42

I’m in Marion County, Florida, looking to find this winged yam in the wild so I can grow it. Where can I go to find it in the wild?

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38 sampath May 1, 2014 at 07:15

I,m sampath from Sri Lanka I,m doing my final year graduate research “Releasing N & K by D.alata decayed leaves for succeeding crops” D.alata have successful here thay had very bulked. so I’ want to some history about D.alata to prepare my report. so can you help me?

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39 Rick Troendle July 27, 2014 at 12:05

Hey, Green.
I took you class last year, and hope to get a chance to take it again.
I found some great purslane, and transplanted it to my garden. OH MY! It is a week, it took over everything. I can’t eat it fast enough.
I also learned about the wide cucumber, and knew I had seen it in my yard before. I hoped it would come back, and it did!
I was, of course, very interested in the winged yam. I searched the neighborhood, and could only find the wrong yam (during fall it had balls not the dog feces looking seed pods).
However, in my yard appeared a vine which looked a lot like the winged yam. Square vine, purple edges, leaves like an arrowhead, it is not circulating around any stick, so I cannot tell the vine twist (although it seems to go Z). The only troubling thing is, single leaves along the stem, not in pairs. I know the winged yam has a purple root, my question is, does the “bad” yam also have a purple root?
I know that may plants are hybrids in nature (have an undergrad degree in biology).
Thanks

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40 Green Deane July 27, 2014 at 17:50

Hmmmm… The winged yam when young can have single leaves not opposite leaves. It grows them when it gets older. The winged yam is usually not purple but there are some purple variaties.

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41 Amelie September 26, 2014 at 18:09

Read your articles on yams A, B and C. Very informative and well written. I live in Washington (state) and am trying to find some D. Alata, but no one seems to carry it. I even went all through Florida’s Craigslist ads to see if anyone was getting rid of it from their yards or gardens. Nothing. As I am highly unlikely to find it growing wild in my neck of the woods, can you point me in the correct direction? Any help would be much appreciated.

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42 Susan December 1, 2014 at 15:40

Years ago my brother was given, by a horticulturist neighbor, what he called the St. Vincent yam, or Black yam. We did some internet searching, and it appears that is a subspecies of D. alata (from one website: http://www.mona.uwi.edu/marcom/newsroom/entry/5775)

He now has what looks like the D. Alata growing all over….but no more purple yams. We are looking for a source of seedstock/root stock for the purple yam, as he says it was more tasty. Does anyone know where this can be found?

I brought the root up to the Pacific Northwest, and grew a nice tuber in my greenhouse, so am interested in the purple version also.

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43 Green Deane December 1, 2014 at 18:15

On facebook contact Andy Firk in Arcadia Florida.

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