知母为百合科植物的根茎。又名薅、莐藩、大芦水、兔子油草、蒜瓣子草、羊胡子草、马马草等。多年生草本,全株无毛;根状茎横生于地面,其上有许多黄褐色纤维,下有多数粗而长的须根。蒴果长卵形,长十至十五毫米,成熟时沿腹缝上方开裂,每室含种子一至二粒。种子三棱形,两端尖,黑色。花期五至六月,果期八至九月。喜生长于向阳干燥的丘陵地及固定的砂丘上。分布于黑龙江、吉林、辽宁、内蒙古、河北、山东、陕西、甘肃等地。知母主要成分为皂甙。根茎含有多量的还原糖和粘液 Anemarrhena is a rhizome of Liliaceae. Also known as 薅, 莐 藩, large water, rabbit oil grass, garlic petals grass, Cotton grass, horse grass and so on. Herbs perennial, glabrous throughout; rhizomes lateral to ground with many tan fibers on them, with many thick, long fibrous roots under them. Capsule long ovoid, length ten to fifteen millimeters, along the crack at the top of the rupture when mature, each room contains seeds one to two. Seeds triangular, pointed at both ends, black. Flowering from May to June, fruit from August to September. Hi growing in sunny dry hills and fixed sand hills. Distributed in Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hebei, Shandong, Shaanxi, Gansu and other places. Anemarrhena main components of saponins. Rhizome contains large amounts of reducing sugar and mucus