In many perennial plants they function in food storage. In many perennial species, stems function in vegetative propagation. Structure of stems. Stems of both grasses and legumes are composed of nodes and internodes. In general, the nodes of a grass stem are more prominent than the nodes of a legume stem.
Buds have the potential to develop into flowers, leaves, roots, or other stems or branches.
In many species, there are modified stems that function in food storage and vegetative propagation. The modified stems usually arise from the lower nodes of the main stem. Rhizomes are horizontal underground stems that can produce new from their nodes. Tillers are secondary stems that arise from nodes at the base of the main stem, and are more or less vertical in position. The crown of a plant is a group of modified stems with very short internodes which occur very close to the soil surface.