Chinese yam
Family
DioscoreaceaeScientific Name
Dioscorea oppositifoliaOther Common Names:
air-potato
Synonyms (former Scientific Names):
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.
Growth Habit
vine
Thorns or Spines
not present
Approximate Flower Diameter
pencil
Dominant Flower Color
Varies:
yellow,
green
Flower Symmetry
not symmetrical
Leaf Hairs
Varies:
no hairs,
has hairs
Leaf Shape
oval
Leaf Arrangement
Varies:
alternate,
opposite
Leaf Margin
lobed
Leaf Structure
simple
Leaf Stalk
longer than leaf
Stem Hairs
no hairs
Stem Cross Section
round or oval
Milky Sap
not present
Root Structure
Varies:
fibrous,
rhizomes present
Life Cycle
perennial
Ochrea
not present
Plant Type
Vine