Mature root of monocots: Wheat

Endodermis with secondary inner periclinal walls

Rhizodermis has been partially torn away

A transverse section of the root of a monocot--wheat (Triticum sp.) at a level above the zone of active water absorption. All tissues are mature.

The xylem is polyarch, the inner tangential wall of all endodermal cells is thickened and impregnated with lignin and suberin, and the rhizodermis is sloughed off. Identify cortex, endodermis, pericycle, phloem, proto- and metaxylem, and seven protoxylem "arms."