Rènpíbù de zhǔyào chéngfèn shì shāiguǎn hé bànbāo.
The phloem is mainly made up of sieve tubes and companion cells.
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The name is literal: the end walls between cells are perforated like a 筛 (shāi, sieve), letting sugary sap flow through. Pair with 导管 (dǎoguǎn, xylem vessel) which carries water in the opposite direction.
