山豆根为豆科植物越南槐 Sophora tonkinensis Gappnep.的干燥根及根茎。有清热触毒,消肿利咽之功。北豆根为防已种植物蝙蝠葛 Menispermum dauricurn DC 的干燥根茎。有清热解毒,祛风止痛之功。为了防止收购和应用发生混淆,现将二者的鉴别特征介绍如下。1 性状鉴别:①山豆根.根茎圆柱形,呈不规则结节状,顶端常残留茎其下生根数条。表面灰褐色至棕褐色,断面皮部深黄棕色,木质部黄白色。微有豆腥所味极苦。②北豆根,呈细长圆柱形,有分枝。表面黄棕 Shandougen is a dried root and rhizome of Sophora tonkinensis Gappnep. There is heat and poison, swelling and pharynx work. North bean root is the dry rhizome of Menispermum dauricurn DC. There are heat and detoxification, Qufeng pain relief. In order to prevent confusion between acquisition and application, the distinguishing features of the two are introduced as follows. 1 Identification of characters: 1 Shandou root. The rhizome is cylindrical and irregularly nodular. The surface is gray-brown to tan, and the cross-section is deep yellow-brown and yellow-white in the xylem. Micro pods taste extremely bitter. 2 North bean root, slender cylindrical, with branches. Surface yellow brown