The moss families (Bryophyta, Musci) of Britain and Ireland

L. Watson and M.J. Dallwitz

Brachytheciaceae

Feather-mosses and Mouse-tail Mosses.

~Hypnaceae

Gametophyte. Pleurocarpous; not dendroid; slender to robust plants, with creeping to ascending stems, branches sometimes homomallous, usually mat or turf forming, or forming patches, or forming wefts. Shoots complanate (rarely), or not complanate. Paraphyllia present (e.g., sometimes in Eurhynchium), or absent (usually). Stems tomentose below, or not tomentose. The leaves of main stems and branches similar in form, or markedly different in form; broadly ovate to narrowly lanceolate; spiral; secund, or not secund (mostly); longitudinally plicate (often, sometimes only weakly), or not plicate. Leaf bases decurrent (in Brachythecium spp., Cirriphyllum, etc.), or not decurrent. The leaves nearly always single-nerved (though occasionally the nerve forked or double, notably in Isothecium myosuroides). The leaf nerves extending beyond the middle of the leaf, but not to the tip (sometimes terminating in a small abaxial projection), or extending to the leaf tip; excurrent (rarely), or not excurrent. Leaf blade apices obtuse, or pointed; apiculate, or not apiculate; apically rounded to acuminate. Leaf blade margins entire, or denticulate, or dentate. Leaf blades not conspicuously bordered. The basal leaf cells somewhat longitudinally elongated to longitudinally much elongated; rounded to linear, or vermicular; smooth. The walls of basal leaf cells thin, or thick; straight. The angular cells clearly differentiated, or not well differentiated. The mid-leaf cells longitudinally much elongated; elongate hexagonal, or rounded, or rhomboidal to linear, or vermicular; nearly always smooth. The walls of the mid-leaf cells thin, or thick; straight.

Plants monoecious, or dioecious; when monoecious, autoecious. Parapyhyses present among the reproductive organs, or absent.

Sporophyte. Capsules exserted; erect (rarely), or inclined to horizontal (usually); symmetrical to asymmetrical; straight, or curved (commonly); sub-cylindric to ovoid, or pyriform, or gibbous; with an externally conspicuous apophysis, or without an externally conspicuous apophysis; smooth; with an annulus (e.g., in some Brachythecium and Eurhynchium species), or without an annulus. Calyptra glabrous; symmetrical; splitting down one side. Capsules with a peristome. The peristome double. The peristome teeth 16 (these horizontally striate below, and papillose above); not grouped; not deeply cleft; thin, membranous, and transversely barred; exteriorly with a fine longitudinal dividing line between the transverse bars. The inner peristome well developed to reduced; shorter than the outer to exceeding the outer (?); with a basal membranous ring (this high); with elongated “processes”. The processes of the inner peristome 16; alternating with the teeth of the outer peristome. The inner peristome ciliate (the cilia usually well developed), or without cilia (sometimes, in Isothecium). The cilia of the inner peristome when present, nodulose or appendiculate. The operculum conical to rostrate. Setae long; usually curved; usually reddish; smooth, or rough.

Ecology. Occurring in basic habitats (commonly), or neutral pH conditions, or acid conditions (uncommonly?).

Cytology. Haploid chromosome number, n = 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 20, and 22 (often variable within species).

Representation in Britain and Ireland. About 50 species. Brachythecium, Cirriphyllum, Eurhynchium, Homalothecium, Isothecium (Mouse-tail Mosses), Kindbergia, Oxyrrhynchium, Platyhypnidium, Pseudoscleropodium, Rhynchostegiella, Rhynchostegium, Scleropodium, Scorpiurium. 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 Hypnales.

Comments. The family and generic descriptions perused for this compilation offer no means of distinguishing Amblystegiaceae from Brachytheciaceae at family level.

Illustrations. • Brachythecium and Homalothecium, with Entodontaceae, Leskeaceae and Tomentypnum: Dixon. BRACHYTHECIACEAE: C, Homalothecium sericeum (Hedw.) Br. Eur.; D, Homalothecium lutescens (Hedw.) Br. Eur.; G, Brachythecium albicans (Hedw.) Br. Eur.; H, Brachythecium glareosum (Spruce) Br. Eur.; I, Brachythecium salebrosum (Web. & Mohr) Br. Eur.; J, Brachythecium campestre B. & S., = B. salebrosum? ENTODONTACEAE: A, Orthothecium intricatum (Hartm.) Br. Eur.; B, Orthothecium rufescens Br. Eur. CAMPYLIACEAE: E, Tomentypnum nitens (Hedw.) Loeske; LESKEACEAE: F, Ptychodium plicatum (Schleich. ex Web. & Mohr) 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. • Brachythecium (9 species), Cirriphyllum, Pseudoscleropodium and Scleropodium: Dixon. BRACHYTHECIACEAE: A, Brachythecium rutabulum (Hedw.) Br. Eur.; B, Brachythecium rivulare Br. Eur.; C, Brachythecium starkei (Brid.) Br. Eur.; D, Brachythecium glaciale Br. Eur.; E, Brachythecium reflexum (Starke) Br. Eur.; F, Brachythecium velutinum (Hedw.) Br. Eur.; G, Brachythecium populeum ((Hedw.) Br. Eur.; H, Brachythecium plumosum ((Hedw.) Br. Eur.; I, Scleropodium cespitans (C. Müll.) L. Koch; J, Scleropodium tourettii (Brid.) L. Koch; K, Pseudoscleropodium purum (Hedw.) Fleisch.; M, Cirriphyllum cirrosum (Schwaegr.) Grout. HYPNACEAE: L, Hyocomium armoricum (Brid.) Wijk & Marg.

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. • Cirriphyllum, Eurhynchium, Isothecium, Rhynchostegiella, Scorpiurium: Dixon. BRACHYTHECIACEAE: A, Cirriphyllum crassinervium (Tayl.) Loeske & Fleisch.; B, Cirriphyllum piliferum (Hedw.) Grout.; C, Oxyrrhynchium speciosum (Brid.) Warnst.; D, Kindbergia praelonga (Hedw.) Ochyra; E, Oxyrrhynchium hians (Hedw.) Loeske; F, Oxyrrhynchium schleicheri (Hedw. f.) Röll; G, Rhynchostegiella pumila (Wils.) E.F. Warb.; H, Rhynchostegiella curviseta (Brid.) Limpr.; I, Rhynchostegiella teneriffae (Mont.) Dirske & Bouman; J, Rhynchostegiella tenella (Dicks.) Limpr.; K, Isothecium alopecuroides (Dubois) Isoviita; L, Isothecium myosuroides Brid.; M, Scorpiurium circinatum (Brid.) Fleisch. & Loeske; N, Eurhynchium pulchellum (Hedw.) Jenn.; O, Eurhynchium striatum (Hedw.) 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. • Eurhynchium, Isothecium and 5 Rhynchostegium species: Dixon. BRACHYTHECIACEAE: A, Eurhynchium meridionale (Br. Eur.) De Not.; B, Eurhynchium striatulum (Spruce) Schimp.; C, Platyhypnidium riparioides (Hedw.) Dixon; D, Rhynchostegium murale (Hedw.) Br. Eur.; E, Rhynchostegium confertum (Dicks.) Br. Eur.; F, Rhynchostegium megapolitanum (Web. & Mohr) Br. Eur.; G, Rhynchostegium rotundifolium (Brid.) Br. Eur.

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. • Brachythecium and Homalothecium: Berkeley. BRACHYTHECIACEAE: 1, Brachythecium albicans (Hedw.) Br. Eur.; a, leaf; b, capsule; c, detached lid of capsule. 2, Homalothecium lutescens (Hedw.) Robins.; a, leaf; b, capsule. 3, Brachythecium plumosum (Hedw.) Br. Eur.; a, leaf; b, capsule. 4, Brachythecium velutinum (Hedw.) Br. Eur.; a, leaf; b, capsule showing peristome; c, detached capsule lid. 5, Brachythecium rutabulum (Hedw.) Br. Eur.; a, leaf; b, capsule; c, part of peristome; d, annulus. 6, Brachythecium rivulare Br. Eur.; a, leaf; b, capsule.

From Berkeley (1863, Plate 5). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Homalothecium sericeum (Berkeley). Homalothecium sericeum (Hedw.) Schimp. a, leaves; b, sporangium. From Berkeley (1863), Plate 12. • Rhynchostegium (with Amblystegiaceae and Campyliaceae): Berkeley. BRACHYTHECIACEAE: 1, Platyhypnidium riparioides (Hedw.) Dixon; a, leaf; b, capsule. 2, Rhynchostegium murale (Hedw.) Br. Eur.; a, leaf; b, immature calyptra; c, capsule. AMBLYSTEGIACEAE: 3, Leptodictyum riparium (Hedw.) Warnst.; a, leaf; b, capsule; c, male inflorescence; d, antheridium. CAMPYLIACEAE: 4, Drepanocladus polygamus (Schimp.) Herdenäs.; a, leaf; b, capsule. 5, Campyliadelphus chrysophyllus (Brid.) R.S. Chopra; a, leaf; b, capsule. 6, Campylium stellatum (Hedw.) Lange & Jens.; a, leaf; b, capsule.

From Berkeley (1863, Plate 6). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Pseudoscleropodium purum, with Calliergonella and Pleurozium: Berkeley. BRACHYTHECIACEAE: 3, Pseudoscleropodium purum (Hedw.) Fleisch., habit; a, adaxial and abaxial views of leaves; b, capsule. HYPNACEAE: 1, Calliergonella cuspidata (Hedw.) Loeske, habit; a, leaf; b, capsule. HYLOCOMIACEAE: 2, Pleurozium schreberi (Brid.) Mitt., habit; a, adaxial and abaxial views of leaves; b, capsule.

From Berkeley (1863, Plate 8). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Homalothecium sericeum, with Hypnaceae and Plagiothecium: Berkeley. BRACHYTHECIACEAE: 6, Homalothecium sericeum (Hedw.) Br. Eur., habit; a, leaves; b, capsule. HYPNACEAE:1, Isopterygiopsis pulchella (Hedw.) Z. Iwats., habit; a, leaves; b, capsule. 3, Pseudotaxiphyllum elegans (Brid.) Z. Iwats., habit; a, leaf; b, capsule after lid shed. 5, Pylaisia polyantha (Hedw.) Br. Eur., habit; a, leaf; b, capsule; c, part of peristome. PLAGIOTHECIACEAE: 2, Plagiothecium denticulatum (Hedw.) Br. Eur., habit; a, leaf; b, capsule. 4, Plagiothecium undulatum (Hedw.) Br. Eur., habit; a, leaf; b, capsule.

From Berkeley (1863, Plate 12). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Brachythecium velutinum (by Curtis).