- the outer coat of a spore, especially a pollen grain.
Origin of exine
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
extine (ˈɛkstɪn, -tiːn, -taɪn)
- botany the outermost coat of a pollen grain or a sporeCompare intine
- The outer layer of the wall of a pollen grain. The exine is composed of the most durable organic polymer known, sporopollenin. Also called extine
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.