常見例句The xylem of ferns only contains tracheids.蕨類植物的木質(zhì)部只含有管胞。It is found in protoxylem and first metaxylem tracheids and vessels.可在原生木質(zhì)部和初始后生木質(zhì)部的管胞和導管中見到。 返回 tracheids