A stem has several functions, including support, conducting water, storing water, producing food and facilitating asexual reproduction. The stem connects the plant's leaves and flowers to its roots. Along with water, the stem carries products from photosynthesis and nutrients to the roots and leaves. It engages in food production through photosynthesis, and it also stores the products made during photosynthesis.
The stem of a plant is characterized by its buds, leaves, nodes and internodes. The bud is an embryonic part of the stem that may differentiate into a flower, a leaf or both. Buds or leaves extend from the node of the stem. The internode is the point between two nodes. Plant stems may grow above or below the ground. When they grow above ground, they are aerial stems. Those that grow below ground are referred to as subterranean stems. Various forms of aerial stems exist, including runners, offshoots, crowns, stolons and spurs. Subterranean stem types include corms, tubers, rhizomes and bulbs. The basic shape of the stem is cylindrical. A stemless or acaulescent plant only has flowers or leaves present. A culm is a stem found in grass plants such as corn and rice. Plant stems can differ in terms of texture and direction. Textures include woody, herbaceous and suffrutescent. A stem's direction may include twining, creeping, prostrate, climbing, erect, decumbent and ascending.