Paraphyses

Paraphyses are part of the fertile spore-bearing layer in certain fungi. More specifically, paraphyses are sterile filamentous hyphal end cells composing part of the hymenium of Ascomycota and Basidiomycota interspersed among either the asci or basidia respectively, and not sufficiently differentiated into specialized, swollen, often protruding cells to be called cystidia.

Paraphyses can also be found in ferns and mosses referring to the filament-like structure that is associated with the fertile sporangia.