On the vascular anatomy and stomates of the lodicules of Zea mays

Abstract

The four lodicules of the male spikelet of Zea mays L. are supplied by one, two, or three traces. In the lower regions of the traces intermediary cells and a few phloem transfer cells occur with the companion cells and sieve tubes. Xylem transfer cells with a variety of wall thickenings intermingle in the lower regions of the traces with tracheary elements. Tracheary elements and sieve tubes in this region do not touch but are separated by the phloem and xylem parenchyma. As the lodicule trace nears the base of the lodicule, intermediary cells and transfer cells diminish. A bundle sheath surrounds the lodicule trace but does not surround the minor veins of the lodicule proper. Within the lodicule proper the trace branches prolifically, and the minor veins become peripherally placed. Most of the minor veins contain vessels and sieve tubes but a few contain sieve tubes alone. Companion cells occur in some veins but not in others. Vessels and sieve tubes frequently touch each other. Many minor veins end simultaneously in sieve elements and tracheary elements but some end in one or the other cell type. Parenchyma cells with wrinkled walls occur near the minor veins. The abaxial epidermis of the upper regions of the lodicule contains stomates.