这个词是什么意思？
Plant tissue that carries water up the root and stem. Xylem cell walls derive most of their strength from LIGNIN. The vessels are similar to PHLOEM sieve tubes but lack companion cells and do not have perforated sides and pores.
中文名称索引；定义为 MeSH 英文原文，尚未逐条译审。MESH:D052584 · MeSH 2026。
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