Dioscorea caucasica

Family Dioscoreaceae. In forests of the lower and middle montane belts of the Black Sea coast of the Caucasus.

Horizontal rhizome up to 30 cm long and 3 cm thick, branched, tuberculate. Stem up to 3 m tall, glabrous in the lower and middle parts; the upper third of it, the underside of the leaves, the petioles and the axes of the inflorescences are pubescent. Lower leaves in false whorls of 2-5; their petioles often twisted; blades ovate, gradually acuminate, with a deeply cordate base, 6-20 cm long, 5-11 cm wide; lobes of the leaf base touching. Upper leaves linear. Flowers of male plants 2-2.5 mm long, single at the nodes of a simple spike at the stem apex or in a compound spike with 2-3 long horizontal lateral branches. Perianth - consisting of a funnel-shaped tube and lobes equal to it, reflexed in a wheel-like manner. Stamens 6, shorter than the perianth; anthers almost spherical. Pistil reduced to a tubercle. Flowers of female plants about 8 mm long, in the nodes of a simple spike. Ovary pyramidal, three-angled, 2.5 times longer than the perianth, with sparse hairs, with 3 bifid stigmas. Fruit a capsule, 25-30 mm wide, 20-25 mm long, with a broadly cordate notch at top and bottom. Seeds elliptic or nearly round, with a thin circular wing, 10-20 mm wide. 2n=20. Flowers in early summer. Tested in Kyiv (overwinters successfully).