Exine
Definition
The tough outer wall of a pollen grain, composed of sporopollenin. Carries the diagnostic sculpture and aperture features and survives most preservation conditions that destroy other biological material.
Related terms
- Aperture
- An opening in the pollen wall through which the pollen tube emerges. Classified by shape into pores (porate), furrows (colpate) and combined...
- Colpus (pl. colpi)
- An elongated, meridionally oriented furrow in the exine. Grains with three colpi (tricolpate) include most eudicot flowering plants. The colpus can carry...
- NPC classification
- A three-digit coding system (Number, Position, Character) for pollen apertures devised by Gunnar Erdtman. Allows rapid, reproducible sorting of unknown grains into...
- Spore
- The reproductive unit of ferns, mosses, and fungi. Structurally distinct from pollen (no aperture in the angiosperm sense; trilete or monolete scars...
- Sporopollenin
- The highly chemically inert polymer forming the outer wall (exine) of pollen grains and spores. Resistant to acid, alkali, oxidation, and biological...
Explained in
- Pollen and Spore MorphologyThe tough outer wall of a pollen grain, composed of sporopollenin. Carries the diagnostic sculpture and aperture features and survives most preservation condit...