| 1. | a vertical series of sieve cells in the phloem, specialized for the conduction of food materials. |
| 2. | a single sieve cell. |
| sieve tube n. A series of cells joined end to end, forming a tube through which nutrients are conducted in flowering plants and brown algae. |
sieve tube
in flowering plants, elongated living cells (sieve-tube elements) of the phloem, the nuclei of which have fragmented and disappeared and the transverse end walls of which are pierced by sievelike groups of pores (sieve plates). They are the conduits of food (mostly sugar) transport.
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