areoler

Areoler is a botanical term used to describe something that bears or relates to areoles. Areoles are small, cushion-like growth points on the stems of cacti and some related succulents from which spines, hairs, or glochids emerge. The word areoler is not common in modern floras; the more standard adjectives are areolate, meaning having areoles, and areolar, relating to areoles. When used as a noun, areoler may refer to a plant that possesses areoles, though this usage is uncommon.

In morphology, areoles arise from modified nodes on the stem and are the defining feature of most cacti, distinguishing them from other groups of succulents. The pattern of areoles—their density, spacing, and arrangement—varies among species and can aid in taxonomic identification and descriptive morphology.

Etymology: areoler derives from the Latin areola, meaning a small open space or little area, with the agent-noun suffix -er to form areoler.

Usage notes: In contemporary texts, prefer areolate (adjective) or areolar (adjective) to describe features, or phrases such as “areole-bearing.” Areoler may appear in historical descriptions or in discussions of morphology, but it is less common in current botanical nomenclature.

See also: Areole, Areolate, Areolar tissue (the latter being a term from anatomy that is unrelated in botany). Related subjects include Cactaceae and cactus morphology.