《中国植物志》|| 苋科 AMARANTHACEAE ||牛膝属 Achyranthes L. ||土牛膝 Achyranthes aspera L.

1. 土牛膝 倒钩草、倒梗草（广州）图版50: 6-11
Achyranthes aspera L. Sp. Pl. 204. 1753; Moq. in DC. Prodr. 13 (2): 314. 1849; Wight, Icon. Pl. Ind. Orient. 5: t. 1777. 1852; Hook. f. Fl: Brit. Ind. 4: 730. 1885; Gagn. in Lecte. Fl. Gener. Indo-Chine 4: 1071. 1936; Becker in Van Steenis, Fl. Males. ser. 1, 4: 88. 1949; 广州植物志148. 1959;海南植物志1: 407. 1964;中国高等植物图鉴1: 609. f. 1217. 1972.
多年生草本，高20-120厘米；根细长，直径3-5毫米，土黄色；茎四棱形，有柔毛，节部稍膨大，分枝对生。叶片纸质，宽卵状倒卵形或椭圆状矩圆形，长1.5-7厘米，宽0.4-4厘米，顶端圆钝，具突尖，基部楔形或圆形，全缘或波状缘，两面密生柔毛，或近无毛；叶柄长5-15毫米，密生柔毛或近无毛。穗状花序顶生，直立，长10-30厘米，花期后反折；总花梗具棱角，粗壮，坚硬，密生白色伏贴或开展柔毛；花长3-4毫米，疏生；苞片披针形，长3-4毫米，顶端长渐尖，小苞片刺状，长2.5-4.5毫米，坚硬，光亮，常带紫色，基部两侧各有1个薄膜质翅，长1.5-2毫米，全缘，全部贴生在刺部，但易于分离；花被片披针形，长3.5-5毫米，长渐尖，花后变硬且锐尖，具1脉；雄蕊长2.5-3.5毫米；退化雄蕊顶端截状或细圆齿状，有具分枝流苏状长缘毛。胞果卵形，长2.5-3毫米。种子卵形，不扁压，长约2毫米，棕色。花期6-8月，果期10月。
产湖南、江西、福建、台湾、广东、广西、四川、云南、贵州。生于山坡疏林或村庄附近空旷地，海拔800-2300米。印度、越南、菲律宾、马来西亚等地有分布。
根药用，有清热解毒，利尿功效，主治感冒发热，扁桃体炎，白喉，流行性腮腺炎，泌尿系结石，肾炎水肿等症。

《Flora of China》|| Amaranthaceae || Achyranthes ||土牛膝 Achyranthes aspera

1. Achyranthes aspera Linnaeus, Sp. Pl. 1: 204. 1753.

土牛膝 tu niu xi

Herbs perennial, 20-120 cm tall. Stem quadrangular, pubescent; nodes slightly inflated; branches opposite. Petiole 0.5-1.5 cm, somewhat hairy; leaf blade broadly obovate or elliptic-oblong, 1.5-7 × 0.4-4 mm, papery, both surfaces hairy, base cuneate or rounded, margin entire or undulate, apex obtuse, with a mucro. Spikes terminal, erect, reflexed after anthesis, 10-30 cm; rachis angular, stout, densely hairy. Bracts lanceolate, 3-4 mm, apex acuminate; bracteoles spiny, shiny, 2.5-4.5 mm, rigid, base 2-winged; wings 1.5-2 mm, membranous, margin entire. Tepals lanceolate, 3.5-5 mm, with a vein. Stamens 2.5-3.5 mm; pseudostaminodes truncate or crenate at apex, fimbriate and ciliate. Utricles ovoid, 2.5-3 mm. Seeds brown, ovoid, ca. 2 mm. Fl. Jun-Aug, fr. Oct. 2n = 42, 48, 84, 96.

Hillsides, waste places, roadsides, riverbanks; 800-2300 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Philippines, Sikkim, Sri Lanka, Thailand, Vietnam; Africa, SW Asia, Europe].

《Flora of North America》|| Amaranthaceae || Achyranthes || Achyranthes aspera

1. Achyranthes aspera Linnaeus, Sp. Pl. 1: 204. 1753.

Centrostachys aspera (Linnaeus) Standley

Plants perennial or annual. Stems 0.4-2 m, pilose or puberulent. Leaf blades elliptic, ovate, or broadly ovate to orbiculate, obovate-orbiculate, or broadly rhombate, 1-20 × 2-6 cm, adpressed-pubescent abaxially and adaxially. Inflorescences to 30 cm; bracts mem-branous; bracteoles long-aristate, spinose; wings attached at sides and base. Flowers: tepals 4 or 5, length 3-7 mm; pseudostaminodes with margins fimbriate at apex, often with dorsal scale. Utricles ± cylindric, 2-4 mm, apex truncate or depressed.

Varieties 6 (2 in the flora): se United States, Mexico, West Indies, Central America, South America, Eurasia, Africa.

Achyranthes aspera is a variable, pantropical species divided into six varieties (C. C. Townsend 1974), two of which occur in the flora. The variety with a long perianth and acuminate leaves has long been called var. aspera; the variety with a short perianth and blunt leaves, var. indica. However, A. Cavaco (1962) showed that the type of var. indica must be the type of the species A. aspera, thus var. indica is a homotypic synonym of var. aspera. Townsend made the combination A. aspera var. pubescens for plants previously called var. aspera.