| | The moss families (Bryophyta, Musci) of Britain and Ireland |
Hump-mosses, Silver-mosses, Thread-mosses, etc.
Excluding Mniaceae and Leptobryum
Gametophyte. Plants “normal”, with leaves containing chlorophyll. Acrocarpous; forming tufts (mostly), or mat or turf forming, or forming patches, or growing through other Bryophytes. Primary stems usually erect. Mature plants when erect, about 2–120 mm high. Plants exhibiting comal tufts of leaves (often, by contrast with Mniaceae), or without comal tufts. Stems not tomentose. The leaves ovate to narrowly lanceolate, or narrowly lanceolate to linear; spiral; crisped when dry (occasionally, e.g. in some Bryum spp.), or not crisped when dry (usually, but commonly flexuose). Leaf bases decurrent (e.g., in some Bryum spp.), or not decurrent. The leaves single-nerved. The leaf nerves extending beyond the middle of the leaf, but not to the tip to extending to the leaf tip; excurrent, or not excurrent; incorporating stereids, or without stereids. Leaf blade apices conspicuously hyaline (Bryum capillare), or not hyaline. Leaf blade margins unistratose, or bi-stratose (Bryum p.p.). Leaf blades bordered (notably in species of Bryum), or not conspicuously bordered. The basal leaf cells longitudinally much elongated (mostly), or somewhat longitudinally elongated; more or less rhomboidal, or linear; smooth. The walls of basal leaf cells thin (mostly), or thick. The angular cells not well differentiated (for the most part), or clearly differentiated (sometimes to some extent, in comal leaves). The mid-leaf cells longitudinally much elongated (mostly), or somewhat longitudinally elongated; more or less rhomboidal (usually), or hexagonal, or linear, or linear to vermicular; smooth. The walls of the mid-leaf cells thin (mostly), or thick.
Plants monoecious, or dioecious; when monoecious, autoecious, or paroecious (commonly), or synoecious. Plants gemmiferous (e.g., Bryum erythrocarpum), or not gemmiferous; the gemmae when present, in leaf axils and or on rhizoids.
Sporophyte. Capsules exserted; inclined to pendulous; symmetrical (usually), or asymmetrical (Plagiobryum); straight, or straight to curved; sub-cylindric to ovoid (Mnium), or clavate, or pyriform (Bryum), or gibbous (Plagiobryum); with an externally conspicuous apophysis (e.g., in some Bryum species, Plagiobryum), or without an externally conspicuous apophysis; smooth. Calyptra large and covering the well-developed capsule, or small; symmetrical; splitting down one side. Capsules with a peristome. The peristome double. The peristome teeth 16; not grouped; not deeply cleft; not perforated; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome well developed to reduced; with a basal membranous ring (usually); usually with elongated “processes”. The processes of the inner peristome 16; alternating with the teeth of the outer peristome. The inner peristome ciliate, or without cilia. The operculum convex, or conical, or mamillate to subulate. Setae long; straight (usually), or curved (cygneous, in Plagiobryum), or flexuose.
Ecology. Occurring in basic habitats, or neutral pH conditions, or acid conditions (commonly). In diverse habitats, from low to high altitudes.
Cytology. Haploid chromosome number, n = 9, 10, 11, 20, 21, 22, 24, 27, 30, 33, and 40 (and occasionally with a supernumerary; many species of Bryum unrecorded).
Representation in Britain and Ireland. About 60 species. Anomobryum (Silver-mosses), Bryum (Thread-mosses), Plagiobryum (Hump-mosses), Rhodobryum (Rose-moss). 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 Bryales.
Illustrations. • Anomobryum filiforme, and 10 Bryum species: Dixon. BRYACEAE: A, Anomobryum julaceum (Schrad. ex Gaertn.) Schimp.; B, Anomobryum julaceum (Schrad. ex Gaertn.) Schimp. var. concinnatum (Spruce) Zetterst.; C, Bryum algovicum Sendtn. ex C. Müll. var. rutheanum (Warnst.) Crundw.; D, Bryum warneum (Röhl.) Brid.; E, Bryum arcticum (R. Br.) Br. Eur.; F, Bryum calophyllum R. Br.; G, Bryum marratii Wils.; H, Bryum knowltonii Barnes; I, Bryum purpurascens (R. Br.) Br. Eur. (a spurious record of this arctic-alpine species for Britain and/or Ireland); J, Bryum mamillatum Lindb.; K, Bryum imbricatum (Schwägr.) Bruch. and 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. • 7 Bryum species: Dixon. BRYACEAE: A, Bryum uliginosum (Brid.) Br. Eur.; B, Bryum lawersianum Philib,; C, Bryum pallens Sw. var. fallax Milde; D, Bryum pallens var. pallens; E, B. weigelii Spreng.; F, Bryum cyclophyllum (Schwaegr.) Br. Eur.; G, Bryum turbinatum (Hedw.) Turn,; H, Bryum pseudotriquetrum (Hedw.) Schwaegr. (see also the next image).
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. • 8 Bryum species: Dixon. BRYACEAE: A, Bryum neodamense C. Müll.; B, Bryum pseudotriquetrum (Hedw.) Schwaegr. var. bimum (Brid.) Lilj. (see also the previous image); C, Bryum creberrimum Tayl.; D, Bryum pallescens Schwaegr. (see also the next image); E, Bryum caespiticum Hedw.; F, Bryum canariense Brid.; G, Bryum intermedium (Brid.) Bland.; H, Bryum capillare 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. • 12 Bryum species, and Rhodobryum roseum: Dixon. BRYACEAE: A, Bryum pallescens Schleich. ex Schweigr. (see also the previous image); B, Bryum donianum Grev.; C, Bryum erythrocarpum agg.; D, Bryum rubens Mitt.; E, Bryum dichotomum Hedw.; F, Bryum radiculosum Brid.; G, Bryum alpinum With.; H, Bryum gemmiparum De Not; I, Bryum muehlenbeckii Br. Eur.; J, Bryum mildeanum Jur.; K, Bryum dixonii Nich; L, Bryum argenteum Hedw.; M, Rhodobryum roseum (Hedw.) Limpr.
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. • Plagiobryum and Rhodobryum (with assorted other taxa): Berkeley. BRYACEAE: 1, Plagiobryum zierii (Hedw.) Lindb.; a, habit; b, leaf; c, leaf cells; d, capsule. 2, Rhodobryum roseum (Hedw.) Limpr.; a, habit; b, leaf; c, capsule; d, part of the outer peristome; e, part of the inner peristome. ORTHODONTIACEAE: 4, Orthodontium gacile Br. Eur.; a, habit; b, leaf; c, calyptra; d, capsule; e, part of the outer peristome. MEESIACEAE: 3, Leptobryum pyriforme (Hedw.) Wils.; a, habit; b, leaf; c, capsule.
From Berkeley (1863, Plate 18). 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’.
