基本解释管胞同根派生 tracheids相关词英汉例句The xylem of ferns only contains tracheids.蕨类植物的木质部只含有管胞。It is found in protoxylem and first metaxylem tracheids and vessels.可在原生木质部和初始后生木质部的管胞和导管中见到。tracheids更多例句