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| The moss families (Bryophyta, Musci) of Britain and Ireland |
Bristle-, Pincushion- and Yoke-mosses.
Excluding Amphidium
Gametophyte. Really acrocarpous, or pleurocarpous (or rather, sometimes ostensibly so, because of branching from beneath the perichaetium); cushion-forming (the leaves usually conspicuously hygroscopic). Mature plants 2–80 mm high. Stems tomentose below, or not tomentose. The leaves neither sphagnoid nor leucobryoid. The leaves ovate to narrowly lanceolate, or linear, or lingulate; spiral; crisped when dry (usually, in Zygodon and Ulota), or not crisped when dry (Orthotrichum); single-nerved. The leaf nerves extending beyond the middle of the leaf, but not to the tip, or extending to the leaf tip; excurrent, or not excurrent. Leaf blade apices obtuse (sometimes), or pointed (usually); apiculate, or not apiculate; apically rounded (occasionally), or apically acute, or acuminate; conspicuously hyaline (Orthotrichum diaphanum), or not hyaline. Leaf blade margins flat, or involute or incurved, or revolute or recurved. Leaf blades not conspicuously bordered. The basal leaf cells somewhat longitudinally elongated, or longitudinally much elongated; rounded, or rhomboidal, or linear; papillose, or smooth. The walls of basal leaf cells thin, or thick; straight. The angular cells not well differentiated. The mid-leaf cells more or less isodiametric; hexagonal to rounded; papillose, or smooth. The walls of the mid-leaf cells thin to thick; straight.
Plants monoecious, or dioecious; when monoecious, autoecious. Plants gemmiferous (e.g., species of Ulota and Orthotricum), or not gemmiferous; the gemmae when present, clustered towards the tips of excurrent leaf nerves (Ulota phyllantha), or borne on the leaf nerves and laminae (Orthotrichum lyelli).
Sporophyte. Capsules immersed to exserted (variable in Zygodon and Orthotrichum, but usually more or less immersed), or exserted (Ulota); erect; straight; more or less ellipsoid (though often long necked); striate and becoming regularly furrowed when dry and empty (8 striae in Ulota and Zygodon, 8 or 16 in Orthotrichum). Calyptra large and covering the well-developed capsule; glabrous (often, with coarse erect hairs), or hairy; symmetrical; plicate (often), or not plicate; splitting down one side, or with two or more splits. Capsules with a peristome (usually, sometimes vestigial), or without a peristome (e.g., some Zygodon species). The peristome when present, usually double, or single (e.g., in some Ulota species, where the endostome can be rudimentary or lacking). The peristome teeth when present, 8 (by fusion of pairs), or 16; not grouped, or in pairs (commonly); not perforated, or perforated; thin, membranous, and transversely barred; when present, exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome shorter than the outer to about equalling the outer; with elongated “processes”, or without “processes” (when present, thinner than the outer peristome). The processes of the inner peristome when present, e.g. in Ulota, Orthotrichium 8, or 16; when present, alternating with the teeth of the outer peristome. The operculum rostellate, or rostrate. Setae very short to long; straight.
Ecology. Mainly growing on rocks or bark.
Cytology. Haploid chromosome number, n = 6, or 10 (+1), or 11, or 12.
Representation in Britain and Ireland. 32 species. Orthotrichum (Bristle-mosses), Ulota (Pincushion-mosses), Zygodon (Yoke-mosses). Northern Scotland, southern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, central southern England, southwest England, Isle of Wight, and Ireland.
Classification. Class Bryopsida; Subclass Bryideae; Order Orthotrichales.
Illustrations. • Zygodon, with Amphidium: Dixon. ORTHOTRICHACEAE: G, Zygodon viridissimus (Dicks.) R. Br. var. viridissimus; H, Zygodon viridissimus var. stirtonii (Schimp. ex Stirt.) Hagen.; I, Zygodon conoideus (Dicks.) Hook. AMPHIDIACEAE: E, Amphidium lapponicum (Hedw.) Schimp.; F, Amphidium mougeotii (Br. Eur.) Schimp.
From Dixon and Jameson (1924), the unscaled screen display approximately doubling the magnifications given with their individual figures. 1, leaf, or stem leaf where these differ; 2, branch-leaf; 3, perichaetial leaf; 4, perigonial leaf; 5, capsule; 6, peristome; 7, calyptra; 8, spores; 9, inflorescence; 10, gemmae; 11, paraphyllia; 12, stoma of capsule; *, plant, or part of one. Qualifications: a, apex; b, base; c, cells at one third from the apex; cv, ventral aspect of cells; cd, dorsal aspect of cells; bc, basal cells; x, section. • Orthotrichum, Ulota, Zygodon: Dixon. ORTHOTRICHACEAE: A, Zygodon forsteri (With.) Mitt.; B, Zygodon gracilis Berk.; C, Ulota coarctata (P. Beauv.) Hammer; D, Ulota drummondii (Hook. & Grev.) Brid.; E, Ulota crispa (Hedw.) Brid. var. norvegica (Grönvall) Smith & Hill; F, Ulota crispa (Hedw.) Brid.; G, Ulota calvescens Wils.; H, Ulota phyllantha Brid.; I, Ulota hutchinsiae (Sm.) Hammar; J, Orthotrichum rupestre Schwaegr.; K, Orthotrichum anomalum Hedw.
From Dixon and Jameson (1924), the unscaled screen display approximately doubling the magnifications given with their individual figures. 1, leaf, or stem leaf where these differ; 2, branch-leaf; 3, perichaetial leaf; 4, perigonial leaf; 5, capsule; 6, peristome; 7, calyptra; 8, spores; 9, inflorescence; 10, gemmae; 11, paraphyllia; 12, stoma of capsule; *, plant, or part of one. Qualifications: a, apex; b, base; c, cells at one third from the apex; cv, ventral aspect of cells; cd, dorsal aspect of cells; bc, basal cells; x, section. • 8 Orthotrichum species: Dixon. ORTHOTRICHACEAE: A, Orthotrichum cupulatum Brid.; B and C, Orthotrichum striatum Hedw.; D, Orthotrichum lyellii Hook. & Tayl.; E, Orthotrichum speciosum Nees; F, Orthotrichum affine Brid.; G, Orthotrichum sprucei Mont.; H, Orthotrichum rivulare Turn.; I, Orthotrichum pumilum Sw; J, Orthotrichum stramineum Brid.; H, Orthotrichum pallens Brid.
From Dixon and Jameson (1924), the unscaled screen display approximately doubling the magnifications given with their individual figures. 1, leaf, or stem leaf where these differ; 2, branch-leaf; 3, perichaetial leaf; 4, perigonial leaf; 5, capsule; 6, peristome; 7, calyptra; 8, spores; 9, inflorescence; 10, gemmae; 11, paraphyllia; 12, stoma of capsule; *, plant, or part of one. Qualifications: a, apex; b, base; c, cells at one third from the apex; cv, ventral aspect of cells; cd, dorsal aspect of cells; bc, basal cells; x, section. • 4 Orthotrichum species: Dixon. ORTHOTRICHACEAE: A, Orthotrichum tenellum Brid.; B, O. pulchellum Brunton; C, O. diaphanum Brid.; D, O. obtusifolium Brid.
From Dixon (1924), the unscaled screen display approximately doubling the magnifications given with his individual figures. 1, leaf, or stem leaf where these differ; 2, branch-leaf; 3, perichaetial leaf; 4, perigonial leaf; 5, capsule; 6, peristome; 7, calyptra; 8, spores; 9, inflorescence; 10, gemmae; 11, paraphyllia; 12, stoma of capsule; *, plant, or part of one. Qualifications: a, apex; b, base; c, cells at one third from the apex; cv, ventral aspect of cells; cd, dorsal aspect of cells; bc, basal cells; x, section. • Orthotrichum and Zygodon, with Amphidium: Berkeley. ORTHOTRICHACEAE: 1, Zygodon conoideus (Dicks.) Hook. & Tayl.; a, habit; b, leaf; c, calyptra; d, capsule. 2, Zygodon viridissimus (Dicks.) R. Br.; a, habit; b, leaf; c, capsule; d, capsule after fall of lid. 4, Orthotrichum cupulatum Brid.; a, habit; b, leaf; c, calyptra; d, capsule; e, part of the peristome. 5, Orthotrichum anomalum Hedw.; a, habit; b, leaf; c, calyptra; d, capsule with lid; e, capsule without lid. 6, Orthotrichum diaphanum Brid.; a, habit; b, leaves; c, calyptra; d, capsule; e, part of the peristome. 7, Orthotrichum pulchellum Brunton; a, habit; b, leaf; c, young calyptra; d, capsule with lid; e, capsule without lid. 8, Orthotrichum striatum Hedw.; a, habit; b, leaf; c, calyptra; d, capsule; e, part of the peristome. AMPHIDIACEAE: 3, Amphidium lapponicum (Hedw.) Schimp.; a, habit; b, leaf; c, calyptrta; d, capsule; e, capsule after fall of its lid.
From Berkeley (1863, Plate 20). The approximate 1 cm scale applies to the whole plant (habit) illustrations only.
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. 2005 onwards. The moss families (Bryophyta, Musci) of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
