Mian Hua Gen

Mian Hua Gen is the root, and particularly the root bark, of cultivated cotton in the genus Gossypium (family Malvaceae), most commonly G. hirsutum or G. herbaceum. The plant is grown as an annual herb in temperate cultivation, reaching 0.6 to 1.5 metres in height, with sturdy, branched stems and alternate, palmately three- to five-lobed leaves on long petioles. Showy solitary flowers borne in the leaf axils open creamy yellow and age to pink or purple, each subtended by a deeply fringed epicalyx of three large bracts. After fertilisation the calyx develops into the familiar cotton boll, a leathery capsule that dehisces at maturity to expose seeds densely clothed in long white lint fibres. The roots collected for medicine are slender, tan-barked, and contain gossypol; the bark is the principally active layer.