植物除了形成正常结构外,还可形成异常结构。这些异常结构的类型、存在部位,在不同的植物中是不同的,它们在中药鉴定中常作为鉴别依据之一,尤其是对根类,根状茎类及茎类药材的鉴定。一、多环性同心环状维管束类型在正常维管组织的外方,出现若干轮同心环状的异常维管组织。这种异常生长,是中央的正常维管束形成之后,在中柱鞘细胞分裂产 In addition to forming normal structures, plants can also form abnormal structures. The types and locations of these abnormal structures are different in different plants. They are often used as identification basis in the identification of traditional Chinese medicines, especially for the identification of roots, rhizomes, and stems. First, multi-ring concentric annular vascular bundle type In the outside of normal vascular tissue, there are several rounds of concentric annular abnormal vascular tissue. This abnormal growth is produced after the formation of normal central vascular bundles in the cells of the occulum sheath