Cortinariaceae

Species of the genus Gymnopilus grow on living or dead trees, living orchids and the roots of the grasses. Cap bright coloured, usually yellow or red, pigment incrusting the hyphal walls, glabrous fibrillose, squamulose, squarrose, floccose or rimose; epicutis formed by hyphal chains which are frequently erect, forming a kind of trichodermium, at least in the centre of the cap; gills adnexed to decurrent, narrow to broad, becoming very brightly and richly rust-coloured in mature carpophores; spore-print amber-brown; spores coloured, double-walled, ellipsoid, warty, rough when seen under an oil-immersion lens; basidia usually clavate, four- or two-spored; marginal cystidia hair-like, facial cystidia usually absent; hymenophoral trama regular; stipe usually yellow, equal or longer than the diameter of the cap; veil present and in some species remains attached to the stipe as a well-developed annulus; context often bitter; hyphae with clamp-connections; the pileus becomes black with KOH, especially when it is covered with spores.