exine

(redirected from Extine)
Also found in: Dictionary, Encyclopedia.

exine

(ĕk′sēn′, -sīn′)
n.
The outer layer of the wall of a spore or pollen grain.

exine

the outer coat of a POLLEN GRAIN, that often has protuberances, spines, etc. The exine also has one or more areas where the wall is thin, forming a pore through which the pollen tube will protrude.
Mentioned in ?