Achyranthes aspera var. indica L.

Centrostachys indica (I/.) Standley, Jour. Wash. Acad. Sci
5: 75. 1915.
Achyranthes aspera indica LSp. PI. 204. 1753.
Achyranthes indica Mill. Gard. Diet. ed. 8. Achyranthes no. 2. 1768.
Achyranthes obtusifolia Lam. Kncyc. 1: 545. 1785.
Cadelaria indica Raf. Fl. Tell. 3: 39. 1837.
Achyranthes aspera Moq. in DC. Prodr. 13 2 : 314. 1849. Not A, aspera L. 1753.
Stachyarpagophora aspera pubescens Maza, Fl. Haban. 93. 1897.
Achyranthes aspera simplex Millsp. Field CoLumb. Mus. Publ. Bot. 2: 36. 1900.
Erect or ascending annual; stems 3-24 dm. high, much branched or rarely simple, the branches spreading or ascending, terete or obscurely quadrangular, cinereous; petioles 3-15 mm. long; leaf -blades rhombic-orbicular or obovate-orbicular, 2-7.5 cm. long and nearly or quite as wide, rounded and very abruptly acute or acutish at the apex, rounded to cuneate at the base, pilose-sericeous on both surfaces or glabrate above, thin; flowers green, spicate, the spikes terminal, 10-40 cm. long, 6-7 mm. thick, obtuse, the rachis pilose or villous; bracts broadly ovate or orbicular, the midnerve indurate and extended into a rigid spine as long as or longer than the body of the bract ; bractlets ovate, long-aristate, shorter than the perianth ; sepals narrowly lanceolate, 4 mm. long, acuminate, green, not nerved, subcartilaginous ; staminodia slightly shorter than the filaments, subquadrilateral, the apex erose-dentate, the dorsal surface produced into a deeply laciniate crest; style longer than the stamens, slender; utricle oblong, truncate above, glabrous; seed oblong, 1.5-2 mm. long, fuscous, dull.
Type locality: India. .
Distribution: Florida and southern Alabama; West Indies; Costa Rica and Panama; also in South America, Africa, eastern and southern Asia, and the islands of the Pacific.

土牛膝（学名：Achyranthes aspera）为苋科牛膝属的植物。