( Russow, 1872) Synonym of perine. See also: endospore, exospore. Perisporium ( Erdtman, 1943) Synonym of perine. Comment: A latinised form of the term perispore. Peritreme (adj.) ( Erdtman and Straka, 1961) Describing a pollen grain with equatorial apertures situated around an outline that is circular in polar view. Comment: The term is not recommended because it is based upon the suffix -treme.

The outer covering of a spore.

the folded membrane of most spores, forming an ornamental external covering.