An artificial class of fungi in the phylum Basidiomycota. It was traditionally divided into two subclasses: Holobasidiomycetidae, delimited by nonseptate basidia and the absence of a yeast phase; and Phragmobasidiomycetidae, frequently with septate basidia and often forming a yeast phase. A typical hymenomycete produces a fruit body or basidiome with spore-bearing basidia organized in a membranelike layer called the hymenium. The fruit bodies are designed to allow for basidiospore discharge into air currents either directly off basidia or after falling from elaborate fertile surfaces. Falling spores, indicative of active discharge, accumulate in powdery masses called spore prints. The shape of the hymenium varies from lamellate (gilled as in mushrooms), poroid (as in conk or bracket fungi), toothed (in hedge hog fungi), coralloid (coral fungi), labyrinthoid (daedaleoid fungi), wrinkled (merulioid fungi), or smooth to diffuse (corticioid fungi). Exceptional hymenomycetes may be aquatic, lack a mycelial phase, or lack a fruit body.