stem

A stem is the main axis of a vascular plant that supports leaves, flowers, and fruit and houses tissues for transport of water, minerals, and sugars. It consists of nodes and internodes, with vascular tissue organized in xylem and phloem. An apical meristem at the tip produces lengthwise growth (primary growth); in woody plants, a lateral meristem called cambium adds girth (secondary growth). Stems may be herbaceous or woody and may store resources.

Diversity: Underground stems include rhizomes; horizontal stems. Stolons or runners spread above ground. Tubers, bulbs and corms are specialized storage stems. Leaves and buds arise from nodes, with terminal buds controlling growth. The arrangement of stems varies by plant habit.

In linguistics, the stem is the base form of a word to which affixes attach, as in teach from which teacher and teaching are derived. In typography, the stem is the vertical stroke of a letter. In biology, stem cells are undifferentiated cells capable of self-renewal and differentiation into various cell types. The acronym STEM stands for science, technology, engineering, and mathematics.