ANOMALOUS SECONDARY THICKENING IN THE ROOTS OF MEDICINAL SPECIES OF CYATHULA OFFICINALIS KUAN.
药用植物川牛膝根中异常次生结构的发育解剖学研究

Cyathula officinalis Kuan., a medicinal plant, is one of the species of Amarantaceae which shows anomalous secondary thickening in its root. The anomalous secondary thickening is by means of a succession of bidirectional cambia. The succeeding cambia initial periodically by periclinal division in a layer of parenchyma cells adjacent to the outmost elements of the phloem derived from the current cambium, each giving rise on its inner side to the xylem of the bundles, on its outer side to the bast. The former appears earlier than the latter. The anomalous vascular bundles are put in spiral order scattered in conjuctive tissues which are parenchyma except those that are sclerenchyma between some xylem strands of the outmost ring. The anomalous secondary structure of this kind may therefore be reconstructed as the primary and early secondary structures are normal.