|MadSci Network: Botany|
The cotton vascular system is representative of an angiosperm vascular system. The conducting cells in xylem are either tracheids or vessel elements. Gymnosperms and seedless vascular plants have mainly tracheids rather than vessel elements. Cotton is an angiosperm or flowering plant so has mainly vessel elements, which stack end to end to form vessels. The conducting cells in angiosperm phloem are sieve-tube elements, also called sieve-tube members. In angiosperms, the sieve-tube elements are associated with specialized parenchyma cells called companion cells. In gymnosperms, albuminous cells occur rather than companion cells. There are many websites with information on xylem, phloem and vascular tissues. There are also many plant anatomy textbooks that can be located at amazon.com. References Plant anatomy glossary Plant tissues Mitchell C. Tarczynski, David N. Byrne, and William B. Miller. 1992. High Performance Liquid Chromatography Analysis of Carbohydrates of Cotton-Phloem Sap and of Honeydew Produced by Bemisia tabaci Feeding on Cotton. Plant Physiol. 98(2): 753-756. Phloem
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