Scientific Name: Dioscorea oppositifolia

Common Name: Chinese yam

Other Common Names: air-potato

Synonyms: Dioscorea batatas

Leaves: Alternate or lower leaves opposite and ovate with a long tapering point, concave sides, and heart-shaped base (cordate). Leaves have 9 to 13 distinct veins. Leaves are thin and without hairs (glabrous) or nearly so above, pubescent or sometimes glabrous beneath. Petioles often longer than the blades. New leaves often have a bronze 'tint'.

Identifying Characteristics: Herbaceous or slightly woody twining vines with fleshy or woody rootstocks, winding upward from left to right to approximately 13 feet in length.This weed is often confused with wild yam, however the vines of wild yam twine upwards from the right to the left, while those of cinnamon vine twine from the left to the right. Cinnamon vine is also commonly confused with the morningglory species. However, the distinct leaf veination and bronze 'tint' of newer leaves help to distinguish this weed from most morningglories.

Flower Seed Head: Greenish-yellow, nearly sessile, in spikes or panicles at the ends of branches, from June-August.

Seed Fruit: Membranous, 3-angled capsule, approximately 3/4 to 1 1/4 inches long and 3/4 inch in diameter

Where Found: Found especially throughout the piedmont and mountainous areas of the southeastern United States.

  • Life cycle: perennial

  • Milky sap: Not Present

  • Plant type: Vine

  • Thorns: Not Present

  • Plant family: Dioscoreaceae

  • Leaf arrangement: opposite; alternate

  • Leaf shape: oval

  • Ochrea: Not Present

  • Leaf margin: lobed

  • Stem hairs: no hairs

  • Flower color: yellow; green

  • Growth habit: vine

  • Stem: round or oval

  • Leaf structure: simple

  • Leaf hairs: has hairs; no hairs

  • Flower symmetry: not symmetrical

  • Flower diameter: pencil

  • Root structure: rhizomes present; fibrous

  • Leaf stalk: longer than leaf