The
pileus is the technical name for what is commonly known as the
cap of a
fungal fruiting body. It is particularly characteristic of
agarics,
boletes, and some
polypores,
tooth fungi, and
ascocarps. Other sporocarp types have less clear differentiation between the pileus and the rest of the fruiting body. Sporocarps with a pileus typically have some type of
hymenophore, such as
lamellae, tubes, or teeth, on the underside of the pileus.
Pilei can be of various shapes the most familiar being hemispherical or convex, with many of these becoming flat as they mature. Many well-known species have this shape, including the button mushroom, various Amanita species and boletes.
Some, such as the parasol mushroom, have distinct bosses or umbos and are described as umbonate. Many fungi, such as chanterelles have a funnel- or trumpet-shaped appearance, the pileus is termed infundibuliform.
Convex
