为玄参科地黄属植物地黄的根状茎。有清热凉血、止血作用,熟地有滋阴补血作用。【植物特征】多年生草本,高5寸～1尺,全株被灰白色长柔毛及腺毛。根状茎肥厚肉质,呈块状,形似白薯,表面橘黄色。叶基生成丛,倒卵形或长椭圆形,叶面多皱,背面带紫色。总状花序,顶生,花冠筒状稍弯曲,紫红色,里面常有黄色带紫的条纹。 Scrophulariaceae is a rhizoma of the yellow plant Rehmannia. There is heat and cooling blood, hemostatic effect, Rehmannia has nourishing yin and blood. 【Plant characteristics】 Perennial herb, 5 inches to 1 foot high, the whole plant is gray villous and glandular hairs. Rhizomes are thick, fleshy and meaty. They resemble sweet potatoes and have an orange surface. Leaf bases generate clumps, obovate or oblong, leafy wrinkled, purple on the back. Racemes, terminal, corolla tube slightly curved, purple, often with yellow-purple stripes inside.