Mature root of monocots: Corn

Pith is present; uncommon in other species

A cross-section of corn (Zea mays) mature root with a polyarch primary xylem. In contrast to wheat in which a metaxylem vessel occupies the center of the vascular cylinder, corn has a well-developed pith in roots which is unusual for these organs. The wide cortex is sclerified beneath the single-layered exodermis. The rhizodermis is partly broken down.

Radial files of metaxylem with one central vessel in each surround the pith. Identify the exodermis, sclerenchyma, cortical parenchyma, endodermis, pericycle, and primary phloem.