Flora of Pennsylvania

Dioscorea villosa

Dioscorea villosa wild yam

Plant grows in the wild/spontaneouslyPlant is native to PA Add to MyPlants View Locations

Wild yam is a rhizomatous, climbing herbaceous vine found in moist woodlands and forests.  It does not have tendrils and instead uses stems to twine around nearby vegetation (or fences).  It spreads either by seeds or branching rhizomes. 

Leaves on long, hairless stalks are mostly alternate, but can also be whorled or opposite near the base of the plant.  Leaf shape varies from heart-shaped to ovate, leaf tips are abruptly pointed. The upper surface of the leaves is smooth and the under surface can have varying degrees of hairyness, occaionsally fully smooth.

Wild yam is dioecious, producing plants with either all male or all female flowers.  Female flowers grow in axillary spikes of 5 to 15 yellowish-green flowers with one flower per node.  Male inflorescences are borne in branched panicles, with 1 to 4 flowers per node on each branch, each flower with 6 yellow stamens.

Frequent in moist woodlands, forests, edges of wetlands & rocky slopes.  Grows best in full or partial sun. Can also grow in some shade but is not likely to flower.

Present throughout the state.

Range:  New England west to Minnesota, south to Georgia and Texas.

Wetland codes
EMP: FAC
NCNE: FAC



Flowers late June to early July.

Fruits August to September.

Flowers  tiny (⅛″), greenish-yellow, 6 tepals fused at the base; in loose clusters (inflorescences) growing from leaf axils

  Staminate inflorescences  widely branched panicles, with 1 to 4 flowers per node

  Pistillate inflorescences   unbranched 2″-8″ long spikes of 5-15 flowers with flowers solitary at each node; each flower positioned on top of ovary

Leaves  mostly alternate, cordate to ovate, with 7 to 11 palmate veins; abruptly acuminate; variously pubescent on the under surface; glabrous 6″ petiole

Stems  twining (no tendrils), glabrous, slender

Fruit  winged capsule with 3 valves; 2 or rarely 1 seed per valve; seeds flat and broadly winged; green when young, turns brown when fully ripe

Height  6 - 17 feet

S-rank:  S5 (Secure)
G-rank:  G4 (Apparently secure)

Dveg (Guest)

Posted on 03 June 2026

this is the first year I'm noticing wild yam growing on our property. It has begun creeping into our wild yard from the woods and today I found some in my raised garden beds. My question is, how aggressive is it?  We are dealing with so many invasive species (autumn olive, bittersweet, vetch, stilt grass...)...is this another plant I need to be ripping out?  Nothing I've read so far leads me to believe it'll be a problem but I want to make sure before it spreads!  Thanks!

 Posted By Admin: @Dveg Wild yam is our native vine, and it’s not considered aggressive or harmful. It can wander a bit at the edges of woods or moist areas, but it doesn’t behave anything like the invasive vines you mentioned (bittersweet, vetch, etc.). It doesn’t smother shrubs or climb high into trees, and it doesn’t form dense, choking mats. You may see a few new shoots pop up where the rhizome runs, but it spreads slowly and stays fairly light in its growth. Most people simply let it be, especially in naturalized or woodland edges. If it’s coming into your raised beds and you’d prefer it not to, you can gently pull or clip those stems, it won’t 'fight back' the way true invasives do. But there’s no need to worry about it taking over or causing ecological harm.
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Dioscorea villosa wild yam

Plant grows in the wild/spontaneouslyPlant is native to PA
Add to MyPlants View Locations
Dioscorea villosa gallery
Plant Summary
perennial herbaceous vine native flower color: yellow-green
Common Names
wild yam yellow yam colicroot devil's-bones