The Families of Mushrooms and Toadstools Represented in the British Isles

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L. Watson and M. J. Dallwitz

Boletaceae

Syn. Strobilomycetaceae, Xerocomaceae (Phylloporus).

Morphology. The fruit-bodies producing basidia and basidiospores; ephemeral; solitary (nearly always), or clustered (e.g., Pseudoboletus); differentiated into a stipe and pileus with the hymenium underneath the latter (the stipe ornamented); small to very large; (2–)4–20(–25) cm across. The mature pileus convex, or more or less flat or somewhat depressed (sometimes, finally). The top of the pileus conspicuously patterned with scales (Strobilomyces), or not patterned with scales (mostly); yellowish-brown, or reddish-brown, or light brown, or dark brown, or olive, or yellow, or purple, or red, or blackish (occasionally), or purplish brown. The fruit-bodies or at least the hymenium, reacting rapidly with a marked colour change when cut or bruised, or showing no conspicuous colour reaction to cutting or bruising; damaged flesh when bruising, turning blackish-blue (Boletus pulverentulus), or greening (in Boletus chrysenteron). The stipe with neither ring nor volva; not developing cavities. The hymenium borne on gills (in Phylloporus only), or porose (nearly always). The hymenial layer readily separable from the supporting flesh. The hymenium not thickening. The hymenophore adnate to decurrent. The hymenophoral trama bilateral. The basidia ‘unmodified’. The basidiospores subglobose, or ovoid to fusoid-cylindric; ballistosporic; yellow-brown, or olive, or rusty brown, or brown (never pinkish, purplish back or fuscous); smooth, or ornamented (smooth or ridged).

The hyphae 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.

Chemical reactions. The context hyphae not xanthochroic. Supposedly not yielding prenylated phenols and quinones.

Ecology. Parasitic (Pseudoboletus parasiticus), or saprophytic, or mycorrhizal; when parasitic, on other fungi (on the ectomycorrhizae of relatives). The fruit-bodies borne on the ground (mostly), or on dead wood. Associated mostly with broad-leaved trees, or with conifers. Found in grassy places, in heathland, in coniferous woodland, in broad-leaved woodland, and in mixed woodland (but mostly in woodland).

British representation. Aureoboletus, Boletus, Buchwaldoboletus, Chalciporus, Leccinum, Phylloporus, Porphyrellus, Pseudoboletus, Strobilomyces, Tylopilus, Xerocomus.

World representation. 415 species; genera 26. “Widespread”.

Classification. Basidiomycota; Basidiomycetes; Agaricomycetidae; Boletales.

Comments. Edible (and often good - notably Boletus edulis, cultured mycelium of which is commonly the source of commercial “mushroom soup”; but a few species such as B. calopus, though not poisonous, have a nasty taste).

Illustrations. • Boletus badius, calopus, edulis, erythropus, impolitus, pulverentulus (LH). • Boletus chrysenteron, luridus, queletii, submentosus, testaceoscaber (LH). • Chalciporus, Leccinum, Pseudoboletus, Strobilomyces, Tylopilus (LH). • Piptoporus betulinus (Berkeley). • Boletus submentosus L. (from Curtis, 1827).


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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