Wild Yam, Colic Root
Synonyms of Dioscorea villosa (20) (Updated on 5-12-21 from Plants of the World Online): Dioscorea cliffortiana Lam., Dioscorea glauca Muhl. ex L.C.Beck, Dioscorea hexaphylla Raf., Dioscorea hirticaulis Bartlett, Dioscorea lloydiana E.H.L.Krause, Dioscorea longifolia Raf., Dioscorea megaptera Raf., Dioscorea paniculata Michx., Dioscorea paniculata var. glabrifolia Bartlett, Dioscorea pruinosa Kunth, Dioscorea quaternata var. glauca (Muhl. ex L.C.Beck) Fernald, Dioscorea repanda Raf., Dioscorea sativa L., Dioscorea villosa var. glabrifolia (Bartlett) S.F.Blake, Dioscorea villosa subsp. glabrifolia (Bartlett) W.Stone, Dioscorea villosa f. glabrifolia (Bartlett) Fernald, Dioscorea villosa var. hirticaulis (Bartlett) H.E.Ahles, Dioscorea villosa var. laeviuscula Alph.Wood, Dioscorea waltheri Desf., Merione villosa (L.) Salisb.
Dioscorea villosa L. is the correct and accepted scientific name for this species. The genus and species were named and described as such by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753.
Plants of the World Online lists 629 species in the Dioscorea genus (as of 5-12-21 when this page was last updated). It is a member of the plant family Dioscoreaceae with 4 genera. Those numbers could change as updates are made by POWO.
The above distribution map for Dioscorea villlosa is from Plants of the World Online. Areas in green are where the species is native and purple where it has been introduced. The map on the USDA Plants Database for North America is the same. The species could have a broader range than the maps show.
The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations.
THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.
I found several colonies of Dioscorea villosa growing in the woods on a friend’s farm on May 3 in 2020. Their preference is light to part shade in moist woodlands and along streams, ponds, marshes although they can grow in drier areas as well. Multiple stems emerge from a single rhizome producing a whorl of leaves. Stems ultimately grow from 7-15 or more feet tall depending on available light.
Common names include Wild Yam or Colic Root, but the rhizomes are not edible…
As I mentioned, the leaves initially grow in a whorl (usually). At that stage, they can be confused with Smilax lasioneura, which I did… In fact, I had all the photos on this page labeled Smilax lasioneura until I went back and saw they were vining… The plants with leaves growing in more of a whorl were, in fact, the Smilax but it was growing in the woods across the highway with no Dioscorea anywhere near. Then I couldn’t find it again… GEEZ!
Dioscorea villosa leaves are kind of heart-shaped (cordate) with heavy veins. While the lower leaves grow in whorls, they grow in an alternate manner on the rest of the vine and are spaced fairly far apart. The upper surface is hairless (glabrous) while the undersides can be either glabrous or have tiny hairs (pubescent). The leaves have petioles (leaf stems) up to 6″ in length.
The vines can grow to 3′ tall before they need support. The stems glabrous and are usually round but some may have ridges, as in the above photo. Stems and petioles can be green, yellow, reddish-green, or even dark red.
Also in the above photo, I believe is the beginning of a pair of inflorescences growing from the leaf axils. Vines either produce all male flowers or all female flowers which are COMPLETELY different. I will wait until I get photos of flowers to write their descriptions. I also need photos of their fruit… There are several websites at the bottom of the page that have great photos and descriptions.
The above photo is a small colony of Dioscorea villosa from another area on the same farm. This group was growing where they received more light at the edge of the woods.
I wasn’t able to get back to these woods later in 2020 to get photos of their flowers, fruit, or seed. HOPEFULLY, I can get back there in 2021 to get more photos so I can write better descriptions.
I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. My farm is in Windsor, Missouri in Pettis County (Henry County is across the street and Benton and Johnson aren’t far away). I have grown over 500 different plants and identified over 100 species of wildflowers (most have pages listed on the right side of the page). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a few horticulturalists I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.
I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at firstname.lastname@example.org. I would enjoy hearing from you especially if you notice something is a bit whacky.
FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
USDA PLANTS DATABASE
MSU-MIDWEST WEEDS AND WILDFLOWERS
ARKANSAS NATIVE PLANT SOCIETY
KANSAS WILDFLOWERS AND GRASSES
PFAF(PLANTS FOR A FUTURE)
LADY BIRD JOHNSON WILDFLOWER CENTER
FRIENDS OF THE WILDFLOWER GARDEN
FLORA OF NORTH AMERICA
NORTH CAROLINA STATE UNIVERSITY
CLIMBERS (UNIVERSITY OF MICHIGAN)
NOTE: The figures may not match on these websites. It depends on when and how they make updates and when their sources make updates (and if they update their sources or even read what they say). Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. In my opinion, Plants of the World Online by Kew is the most reliable and up-to-date plant database and they make updates on a regular basis. I make updates at least once a year and when I write new pages but I do get behind. We are all a work in progress. 🙂