芝麻 zhi ma

Sesamum orientale Linnaeus.

Herbs annual, erect, to 1.2 m tall. Stems branched or unbranched, 4-angled, finely pubescent to glabrescent. Leaves opposite or alternate; petiole 3-11 cm on lower leaves; leaf blade lanceolate to ovate, variously 3-parted, 4-20 X 2-10 cm; upper stem leaves oblong to linear-lanceolate, 0.5-2.5 cm wide, base cuneate, margin entire. Flowers white, pink, or mauve-pink with darker markings. Calyx persistent. Corolla 1.5-3.3 cm. Capsule narrowly oblong, rounded at base, 1.5-3 cm X 6-7 mm; beak broad, short. Seeds horizontally arranged, double fringe conspicuous; testa white, brown, or black when ripe, smooth. 2n = 26*.

Widely cultivated in China as a crop for seed oil; origin uncertain, cultivated worldwide, especially in tropical countries.