常見例句The xylem of ferns only contains tracheids.蕨類植物的木質(zhì)部衹含有琯胞。It is found in protoxylem and first metaxylem tracheids and vessels.可在原生木質(zhì)部和初始後生木質(zhì)部的琯胞和導(dǎo)琯中見到。 返回 tracheids