The term pellis refers to the cellular cortical layers of a mushroom

Mushroom

A mushroom is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground on soil or on its food source. The standard for the name "mushroom" is the cultivated white button mushroom, Agaricus bisporus; hence the word "mushroom" is most often applied to those fungi that...

. The term was introduced by Dutch mycologist Cornelis Bas

Cornelis Bas

Dr. Cornelis Bas is a noted Dutch mycologist.Dr. Bas was born in Rotterdam and graduated in Biology at Leiden University in 1954. In 1953, he began working at the National Herbarium of the Netherlands, as curator for the fungi, in particular, the Agaricales...

 in 1969, who distinguished different layers of the pellis as suprapellis, mediopellis and subpellis. He also distinguished various topographies of the pellis. For example, pileipellis refers to the cuticle of the mushroom pileus

Pileus (mycology)

The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...

 (or cap), while stipitipellis is the cuticle of the stipe

Stipe (mycology)

thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...

(the stem).