1) Of leaves or flowers 
moving from roots to leaves, e.g. of molecular signals in plants.
Describes the development of structures (such as spores) in succession from the base towards the apex. 
• (a.) Developing from below towards the apex, or from the circumference towards the center; centripetal; -- said of certain inflorescence.
<botany> Describes a plant part which is arising or developing in a longitudinal sequence beginning at the base and proceeding towards the apex. ... (13 Nov 1997) ... 
Describes the development of structures (such as spores) in succession from the base towards the apex.
A·crop'e·tal adjective [ Greek 
Type: Term Pronunciation: ă-krop′ĕ-tăl Definitions: 1. In a direction toward the summit. 2. Produced successively toward the apex, with the youngest conidium formed at the tip and the oldest at the base of a chain of conidia; pertaining to asexual spore production in fungi by successive budding of the distal spore in a spore ch...
[adj] - (botany) of leaves or flowers
acropetal, acropetally 1. Developing upward from the base toward the apex or tip. 2. Rising toward the summit.
adjective of leaves or flowers; developing or opening in succession from base to apex
(of an inflorescence) developing upward, toward the apex.