Ko te whai i te xylem tracheids tautuhi i te tipu vascular ranei Tracheophytes. Tracheids e tohu, pūtau xylem elongated, te māmā rawa o nei i tonu taiepa tuatahi pūtau, me te lignified taiepa tuarua thickenings i roto i te ahua o te porowhita, hoops, whatunga reticulate ranei. atu tracheids matatini ki taiepa taiepa rite valve-rite i huaina pnosperytes. ko te xylem gymnosperytes me te tahi atu pūtau e mohiotia hoki rite te puku puku puku, engari he rite ki te puku puku. Ko te hanga o te tahi atu pūtau e whai i te pnoophory, ko te puranga o te tahi atu pūtau e mohiotia anake rite xylem gymnosperytes.
Ko ngā kōpaki