凹头苋 ao tou xian

Amaranthus ascendens Loiseleur-Deslongchamps; A. lividus Linnaeus; A. lividus var. ascendens (Lois) Thellung-Blom; Euxolus ascendens (Loiseleur-Deslongchamps) H. Hara.

Stem ascending, light green or purple, 10-30 cm tall, branched from base, glabrous. Petiole 1-3.5 cm; leaf blade ovate or ovate-rhombic, 1.5-4.5 × 1-3 cm, base cuneate, margin entire or slightly undulate, apex notched, with a mucro. Flower clusters axillary, those of terminal clusters erect spikes or complex thyrsoid structures. Bracts and bracteoles oblong, shorter than 1 mm. Tepals light green, oblong or lanceolate, 1.2-1.5 mm, with a midvein adaxially, apex acute. Stamens slightly shorter than perianth; stigmas 3 or 2, falling off when utricles ripen. Utricles exceeding perianth, compressed-ovoid, ca. 3 mm, indehiscent, slightly rugose to nearly smooth. Seeds black to brownish black, circular, ca. 1.2 cm in diam. Fl. Jul-Aug, fr. Aug-Sep. 2n = 34.

Fields, waste places. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Yunnan, Zhejiang [Japan, Laos, Nepal, Sikkim, Vietnam; N Africa, Europe, South America].