The Families of Mushrooms and Toadstools Represented in the British Isles


L. Watson and M. J. Dallwitz


~ Helvellaceae.

Morphology. The fruit-bodies producing asci and ascospores; persistent; in R. undulata, discoid, or cushion-shaped (at first disc-shaped, later cushion-shaped and irregularly lobed, 2–8 cm high; very tough); sessile; medium sized to very large; in R. undulata, about 6–24 cm across; 2–8 cm high; blackish; apothecial (superficial); ascus-bearing hymenial layer more or less flat, or everted; stromata absent. The asci cylindrical; asci operculate; without obvious apical thickening; thin walled (operculate). The walls of the asci not staining blue with iodine. The ascospores smooth to ornamented (minutely rough); simple; tetranucleate; without appendages; without a mucilaginous sheath.

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

Ecology. Saprophytic. The fruit-bodies borne on the ground. Found in coniferous woodland (R. undulata in coniferous debris, especially after fires).

British representation. 1 species in Britain (R. undulata); Rhizina.

World representation. 1–2 species; genera 1 (? - Rhizina). North temperate.

Classification. Ascomycota; Ascomycetes; Pezizomycetidae; Pezizales.

Illustrations. • Rhizina undulata (LH).

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.’.