The Families of Mushrooms and Toadstools Represented in the British Isles

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L. Watson and M. J. Dallwitz

Agaricaceae

E.g., ‘True Mushrooms’ and ‘Parasol Mushrooms’.

Including Lepiotaceae, Podaxaceae. For the present, excluding taxa long referred to Coprinaceae, q.v.

Morphology. The fruit-bodies producing basidia and basidiospores; ephemeral; simple; nearly always solitary; differentiated into a stipe and pileus with the hymenium underneath the latter; small to very large; (1–)3–26 cm across. The mature pileus convex to parasol-shaped, or more or less flat or somewhat depressed (only occasionally). The fruit-bodies brightly pigmented (rarely), or not brightly pigmented. The top of the pileus conspicuously patterned with scales (notably in Lepiota), or not patterned with scales; white or whitish, or cream or yellowish, or buff, or buff and light brown, or buff and dark brown, or straw-coloured, or honey-coloured, or light brown, or dark brown, or light brown and dark brown, or yellow (or yellowish), or green (rarely - Lepiota grangei). The fruit-bodies reacting rapidly with a marked colour change when cut or bruised, or showing no conspicuous colour reaction to cutting or bruising; damaged flesh when colouring, turning brownish (Agaricus subperonatus), or turning red (Agaricus langei), or yellowing (Agaricus placomyces, A. xanthoderma); smelling of aniseed (in Agaricus arvensis), or with a faintly sweetish or pleasant aroma (e.g., Agaricus langei), or with no particular odour other than an ordinary fungoid one. The stipe bearing a ring but no volva (though the ring is sometimes rudimentary in Lepiota). The hymenium borne on gills; not thickening. The hymenophore free. The hymenophoral trama not bilateral. The basidia ‘unmodified’. The basidiospores ballistosporic; hyaline, or white, or pink, or olive, or brown, or fuscous, or brown-black, or blue-black (variable in colour, but never rusty- or cinnamon-brown, by contrast with Bolbitiaceae); smooth; with a germ pore (often), or without a germ pore; amyloid, or inamyloid.

The hyphae with clamp connections, or without clamp connections. The hyphal walls lamellate, with a thin, electron-dense outer layer and a relatively thick, electron-transparent inner layer. The hyphae monomitic. The generative hyphae inflated. Spaerocysts not occurring among the context hyphae.

Ecology. Saprophytic (usually not mycorrhizal?). The fruit-bodies borne on the ground. Found in grassy places, in coniferous woodland, in broad-leaved woodland, in mixed woodland, and in places modified by human activities.

British representation. Agaricus, Allopsalliota, Chamaemyces, Chlorophyllum, Cystolepiota, Lepiota, Leucoagaricus, Leucocoprinus, Macrolepiota, Melanophyllum, Micropsalliota, Psalliota, Schulzeria.

World representation. 918 species; genera 51. Cosmopolitan.

Classification. Basidiomycota; Basidiomycetes; Agaricomycetidae; Agaricales.

Comments. Variously poisonous (or suspect), or edible (notably some Lepiota species, as well as various Mushrooms of the genus Agaricus - but beware of the Yellow Stainers, A. xanthodermus and A. placomyces).

Illustrations. • Agaricus bisporus, A. bitorquis, A.campestris, A. comtulis, A. subperonatus (LH). • Agaricus arvensis, A. semotus, A. silvicola, A. urinascens (LH). • Lepiota aspera, boudieri, castanea, clypeolaria, cortinarius, cristata, fuscovinacea, grangei (LH). • Cystolepiota, Leucoagaricus, Melanophyllum (LH). • Chlorophyllum rhacodes, Macrolepiota excoriata, Macrolepiota procera (LH). • Agaricus arvensis, A. campestris, and Leucocoprinus cretaceus (Berkeley). • Lepiota cristata and L. rachodes (Berkeley).


To view the illustrations with captions giving names in current use, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, source references, and other relevant material.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2008 onwards. The families of mushrooms and toadstools represented in the British Isles. Version: 6th March 2015. delta-intkey.com’.

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