Protoxylem and metaxylem vessel elements and sieve-tube elements in a longitudinal section of Cucurbita stem - prepared slide 4x objective

Photographer

Clayton, Michael W.

Summary

• Photomicrograph
• Both metaxylem and protoxylem are primary tissues derived from the growth of an apical meristem. The metaxylem vessels typically differentiate after elongation ends and have complete pitted secondary walls. Protoxylem vessels typically differentiate during elongation and have incomplete secondary walls. These are organized as hoops (annular), or as helices.