Plant Cell Development 3 Small 72×320 Medium 144×640 Large 230×1024 Download Tiff Original 539×2400 | (306.2 KB) Description Third developmental stage of sieve tubes, companion cells, and phloem parenchyma. "The pits in the cross-walls of the sieve tubes become perforations, and the nuclei gone from the cells composing the tube." -Stevens, 1916 Keywords companion cells, phloem parenchyma, plant anatomy, plant cells, procambial plant cells, sieve tubes Galleries Cellular Botany Source: William Chase Stevens Plant Anatomy (Philadelphia, PA: P. Blakiston, 1916)
