ray

In plant anatomy, a vascular ray, also known as a medullary ray, is a band of cells that extends radially from the cambium into both the xylem and phloem of a plant's root or stem. These rays are composed of ray parenchyma, which are cells arranged horizontally and radially.123

Vascular rays function in the radial conduction of fluids and appear like spokes of a wheel in a cross-section. They assist in transporting substances from the vascular bundles to adjacent tissues. This tissue connects the pith with the cortex in herbaceous dicotyledonous stems.142