The Families of Mushrooms and Toadstools Represented in the British Isles

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L. Watson and M. J. Dallwitz

Helotiaceae

Cf. Leotiaceae?.

Anamorphic forms occurring (very varied, known for a few taxa including the Chalara Ash disease).

Morphology. The fruit-bodies producing asci and ascospores, or not developing asci, probasidia or basidia; discoid, or cupulate (glabrous or downy); clustered, or solitary; stipitate to sessile; discrete, or coalescing; tiny to small; 0.5–1 cm across (with sampling restricted to the species illustrated); brightly pigmented (often), or not brightly pigmented; when brightly pigmented (e.g.) orange, or yellow, or green, or purple; apothecial; stromata usually absent. The asci cylindrical; asci inoperculate; thin walled. The walls of the asci usually with a small but distinct apical J+ or J- ring. The ascospores ellipsoid, or elongate; smooth; usually hyaline; septate, or simple.

The hyphae without clamp connections. The hyphal walls lamellate, double layered, with both layers electron dense.

Ecology. Saprophytic. The fruit-bodies usually on dead wood (bursting through decaying branches, on old stumps, etc., but sometimes on decaying herbaceous tissue, and occasionally fungicolous). Found in broad-leaved woodland and in mixed woodland, or in coniferous woodland (?).

British representation. Allophylaria, Ascocalyx, Ascocoryne, Ascotremella, Belonioscypha, Bisporella, Bryoscyphus, Bulgariella, Calycella, Calycina, Cenangium, Chalara, Chlorencoelia, Chlorociboria, Chloroscypha, Claussenomyces, Clithris, Corynella, Crocicreas, Crumenula, Crumenulopsis, Cudoniella, Cyathicula, Cystopezizella, Dencoeliopsis, Discorehmia, Durella, Encoeliopsis, Erikssonopsis, Eubelonis, Gelatinopsis, Gloeopeziza, Godronia, Gorgoniceps, Grahamiella, Gremmeniella, Grovesiella, Helotium, Heterosphaeria, Heyderia, Hymenoscyphus, Ionomidotis, Lagerbergia, Lagerheima, Llimoniella, Micropodia, Mitrula, Mniaecia, Neobulgaria, Ombrophila, Pachydisca, Parorbiliopsis, Patellea, Patinellaria, Pezizella, Phaeangellina, Phaeohelotium, Pocillum, Pragmopora, Pseudohelotium, Sarcoleotia, Scleroderris, Scutularia, Septatium, Skyathea, Stamnaria, Strossmayeria, Symphyosirinia, Tympanis, Unguiculariopsis, Velutarina, Xylogramma.

World representation. About 650 species; genera about 110. “Widespread”.

Classification. Ascomycota; Ascomycetes; Leotiomycetidae; Helotiales.

Comments. ‘Inoperculate Discomycetes’, with interascal tissue of simple paraphyses. Including the notorious European dieback disease of Ash (Fraxinus exelsior). This is associated with the anamorph Chalara fraxinea, formally described only in 2006 and linked to its sexual stage - Hymenoscyphus pseudoalbidus - only in 2010. The symptoms seem to have been first recorded in Poland in 1992, but the disease now afflicts host trees throughout Europe, with ecologically and aesthetically disastrous efects on woodlands and hedgerows on calcareous soils. Its rapid spread presumably reflects a recent increase in virulence, no doubt assisted by irresponsible failure to control human transport of unprocessed wood and living plant material.

Illustrations. • Ascocoryne sarcoides, Bisporella citrina, Chlorociboria aeruginascens (LH). • Ascocoryne sarcoides (Berkeley). • Ascocoryne sarcoides and Chlorencoelia versiformis (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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