Term and pronunciation Basipetal (Bay-sipit-al)
Etymology From Latin: Base + Petal - with the sense of moving in a specified direction.
The growth or development from the apex (shoot tip and root tip) to the base. Meaning that the oldest parts are nearest the apex and the youngest parts are near the base. The opposite action is called acropetal where the youngest parts are at the apex.
Usage and examples
Basipetal maturation: This is when the flowers mature in a downward fashion from the top of the stem. CRM over at WAB gave Button snakewort (Liatris spicata) as an example of a plant that flowers in this way.
The first written usage of basipetal as recorded by the OED is that published by Student in 1869 in reference to basipetal formation of foliary parts.
"basipetal, adj.". OED Online. December 2012. Oxford University Press.
11 February 2013
Allaby, M. (2012) Oxford Dictionary of Plant Sciences, Oxford, Oxford University Press.