NPC Classification
Definition
A three-digit coding system (Number, Position, Character) for pollen apertures devised by Gunnar Erdtman. Allows rapid, reproducible sorting of unknown grains into morphological groups before full species identification.
- Devised by
- Gunnar Erdtman
- Code structure
- Three digits: Number, Position, Character
- Purpose
- Rapid preliminary sorting of pollen apertures
- Next step
- Followed by full morphological species identification
Common questions
Why is a preliminary sorting code useful before full species identification?+
Palynologists examining forensic samples often need to triage large numbers of grains quickly, and grouping them by aperture number, position, and character narrows the candidate taxa before the slower work of matching against reference collections begins.
Is NPC classification alone sufficient to identify a pollen grain to species?+
No, it only groups grains by aperture pattern; distinguishing between species within the same NPC group still requires examining exine sculpturing, size, and shape under higher magnification, often with reference keys.
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...
- Exine
- The tough outer wall of a pollen grain, composed of sporopollenin. Carries the diagnostic sculpture and aperture features and survives most preservation...
- 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...