Dioscorea esculenta (Lour.) Burkill (Dioscoreaceae)

Scientific name
Dioscorea esculenta (Lour.) Burkill
Family name
Dioscoreaceae
Common name
Lesser yam, Asiatic yam (English); togeimo, togedokoro (Japanese)
Local name
Man musua, man chuak
Herbaceous, pubescent, often prickly, climbing annual. Stem terete, twining to the left, prickly at the base and less so upwards; roots thorny in wild plants, often thornless in cultivated plants. Tubers 4–20 per plant, thrust downwards from a corm, on stolons 5–50 cm long; mature tubers short, cylindrical, sometimes lobed, 8–20 × 2–5 cm; skin brown or grey-brown, thin, often rough with indurated bases of rootlets; flesh white; bulbils absent. Leaves alternate, simple, cordate, 10–15 × 10–17 cm, acuminate, with 9–13 veins, lateral veins regular but not conspicuously ladder-like; petiole length 1–1.5 times that of blade, often with 2 prominent spines at the base. Inflorescence unisexual. Male inflorescence solitary in distal leaf axils, usually bearing one flower at a time along the axis but up to 70 or more in total. Female inflorescence on downcurved spike-like racemes, solitary from upper leaf axils, up to 40 cm long. Fruit a reflexed capsule, 27 × 12 mm. Seeds winged all around.
Traditional medicinal use
Functionality
Functional constituents
Common climber in the subhumid and humid tropics; often cultivated in lowland areas with well-drained soil (pH 5.5–6.5). Propagated by planting small whole tubers on mounds, ridges, or flat ground. Tubers and larger bulbils are peeled, boiled, and cooked in curries or as a sweet.
Tubers contain 70–80 g water, 1.3–2.1 g protein, 0.1–0.3 g fat, 26–36 g carbohydrates (25 g starch, 1–11 g sugar), 0.2–1.5 g fibre, 0.5–1.2 g ash, 0.017 mg vitamin A, 0.08 mg vitamin B1, 0.02 mg vitamin B2, and 20.3 mg vitamin C per 100-g serving.
Bulb
Bulb