caules

Caules is a botanical term referring to the stems or main axes of plants. The singular caulus, from Latin caulus meaning “stem” or “stalk,” is used in some taxonomic and descriptive writings; its plural forms include cauli and caules. In English botanical usage, caulus appears in technical or historic texts, while caulescent and acaulescent describe plants with or without a distinct stem.

A caulus consists of stalk tissue bearing leaves at nodes and connecting roots with shoots. It provides structural support, houses vascular tissue, and serves as the conduit for water, minerals, and photosynthates between roots and shoots. The morphology of caules varies: some are herbaceous and slender; others are woody and robust. In monocots, stems may have scattered vascular bundles; in many dicots, bundles form a ring.

Leaves may be cauline, meaning they arise from the stem rather than the base; cauline leaves can be opposite or alternate depending on species. When a plant has a well-developed stem, it is described as caulescent; if the stem is not obvious, the plant is described as acaulescent.

See also references include caulus, cauline, caulescent, and acaulescent, which relate to the presence, absence, and characteristics of the stem in plants.