Hygrocybe is a genus of agarics (gilled fungi) in the family Hygrophoraceae. Called waxcaps in English (sometimes waxy caps in North America), basidiocarps (fruit bodies) are often brightly coloured and have dry to waxy caps, white spores, and smooth, ringless stems. In Europe they are characteristic of old, unimproved grasslands (termed waxcap grasslands) which are a declining habitat, making many Hygrocybe species of conservation concern. Four of these waxcap-grassland species, Hygrocybe citrinovirens, H. punicea, H. spadicea, and H. splendidissima, are assessed as globally "vulnerable" on the IUCN Red List of Threatened Species. Elsewhere waxcaps are more typically found in woodlands. Most are ground-dwelling and all are believed to be biotrophs. Around 150 species are recognized worldwide. Fruit bodies of several Hygrocybe species are considered edible and are sometimes offered for sale in local markets. Taxonomy History Hygrocybe was first published in 1821 by Swedish mycologist Elias Magnus Fries as a subsection of Agaricus and in 1871 was raised to the rank of genus by Kummer. In several papers, Karsten and Murrill used the name Hydrocybe, but this is now taken as an orthographic variant of Hygrocybe. The generic name is derived from the Greek ῦγρὁς (= moist) + κυβη (= head). Despite its comparatively early publication, the genus Hygrocybe was not widely accepted until the 1970s, most previous authors treating it as a synonym of Hygrophorus, a related genus of ectomycorrhizal agarics. Current status Recent molecular research, based on cladistic analysis of DNA sequences, has shown that Hygrocybe sensu lato is paraphyletic and does not form a single clade within the Hygrophoraceae. As a result, many species formerly referred to Hygrocybe have been transferred to the genera Chromosera, Cuphophyllus, Gliophorus, Gloioxanthomyces, Humidicutis, Neohygrocybe, or Porpolomopsis. This leaves Hygrocybe sensu stricto as a smaller but more cohesive genus of species related to the type, Hygrocybe conica. Description Fruit bodies of Hygrocybe species are all agaricoid, most (but not all) having smooth to slightly scaly caps that are convex to conical and dry to waxy or viscid when damp. Many (but not all) are brightly coloured in shades of red, orange, or yellow. Where present, the gills beneath the cap are often equally coloured and usually distant, thick, and waxy. One atypical South American species, Hygrocybe aphylla, lacks gills. The stems of Hygrocybe species lack a ring. The spore print is white. Fruit bodies of some species, notably Hygrocybe conica, blacken with