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| The families of mushrooms and toadstools represented in Britain and Ireland |
~ 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).
Representation in Britain and Ireland. 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). RHIZINACEAE. Rhizina undulata. Sunesen & Dahlstrøm, in Lange & Hora (1965).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2008 onwards. The families of mushrooms and toadstools represented in Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
