acropetal

Acropetal is an adjective used in botany to describe a directional pattern of development or maturation along a plant axis, moving from the base toward the apex (the tip). In acropetal development, older structures are located basally and younger structures mature as one proceeds toward the apex. The opposite pattern is basipetal, where maturation progresses from the apex toward the base.

The term is commonly applied to processes such as flower and leaf initiation, as well as tissue differentiation. For example, in many inflorescences, flowers may open in acropetal order, with basal flowers maturing before those at the apex. Similarly, on a growing shoot, leaf primordia can develop in an acropetal sequence from the base toward the tip, so older leaves lie nearer the base while newer leaves occupy positions toward the apex. Acropetal patterns can also describe the progression of vascular differentiation or other developmental events along a stem.

Etymology: from Latin acropetalus, combining acro- meaning 'tip' with petere meaning 'to seek' or 'to go toward'. The term is primarily used in descriptive botany and plant anatomy; in other disciplines the related concept basipetal is more commonly encountered.

See also: basipetal, apical development, plant development.