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| The moss families (Bryophyta, Musci) of Britain and Ireland |
Excluding Rhytidium.
~Hypnaceae
Gametophyte. Pleurocarpous; not dendroid; forming patches, or forming wefts (robust mosses, usually forming patches, or lax, coarse wefts). Primary stems erect to procumbent (the stems usually forked, often pinnately branched). Shoots complanate, or not complanate. Paraphyllia present (only in Hylocomium), or absent. Pseudoparaphyllia present, or absent. Stems reddish. The leaves of main stems and branches similar in form, or markedly different in form (especially in Hylocomium); bilaterally symmetrical; ovate to lanceolate (or deltoid); spiral; (falcato-) secund, or not secund; longitudinally plicate (in Hylocomium), or not plicate. Leaf bases almost sheathing, or not sheathing; not decurrent. The leaves shortly double-nerved, or nerveless. The leaf nerves when present, not extending beyond the middle of the leaf, or not extending beyond the middle of the leaf to extending beyond the middle of the leaf, but not to the tip. Leaf blade apices pointed; apiculate, or not apiculate; apically rounded, or apically acute, or acuminate. Leaf blade margins flat, or involute or incurved, or revolute or recurved; usually at least distally 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; narrowly rhomboidal to linear, or vermicular; smooth. The walls of the mid-leaf cells thick; straight.
Plants dioecious.
Sporophyte. Capsules exserted; inclined, or horizontal, or inclined to horizontal; symmetrical to asymmetrical; usually at least somewhat curved, or straight to curved; sub-cylindric to ovoid, or pyriform, or gibbous; with an externally conspicuous apophysis, or without an externally conspicuous apophysis; smooth; without an annulus. Calyptra 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; shorter than the outer to exceeding the outer (?); with a basal membranous ring; with elongated “processes” (these usually keeled). The processes of the inner peristome 16. The inner peristome ciliate. The cilia and processes of the endostome not united into a conical lattice. The cilia of the inner peristome nodulose or appendiculate (nodulose). Setae red; smooth (usually), or rough (then papillose).
Ecology. In wet places, or mesophytic, or xerophytic; occurring in basic habitats, or neutral pH conditions, or acid conditions. In diverse habitats.
Cytology. Haploid chromosome number, n = 5, 6, 7, 10, and 12.
Representation in Britain and Ireland. 9 species. Hylocomiastrum (Wood-moss), Hylocomium (Wood-mosses), Loeskeobryum, Pleurozium (Feather-moss), Rhytidiadelphus (Shaggy- and Turf-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 Hypnales.
Illustrations. • Hylocomiastrum, Hylocomium and Rhytidiadelphus (with Rhytidiaceae): Dixon. HYLOCOMIACEAE: A, Pleurozium schreberi (Brid.) Mitt.; B, Hylocomium splendens (Hedw.) Br.Eur.; C, Hylocomiastrum umbratum (Hedw.) M. Fleisch.; D, Hylocomiastrum pyrenaicum (Spruce) M. Fleisch.; E, Loeskobryum brevirostre (Brid.) M. Fleisch.; F, Rhytidiadelphus loreus (Hedw.) Warnst.; G, Rhytidiadelphus squarrosus (Hedw.) Warnst.; H, Rhytidiadelphus triquetrus (Hedw.) Warnst. RHYTIDIACEAE: I, Rhytidium rugosum (Hedw.) Kindb.
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. • Hylocomium, Loeskeobryum and Rhytidiadelphus, with Hyocomium (Hypnaceae): Berkeley. HYLOCOMIACEAE: 1, Hylocomium splendens (Hedw.) Br. Eur., habit; a, leaf; b, capsule. 2, Loeskeobryum brevirostre (Brid.) M. Fleisch., habit; a, leaves, abaxial (left) and adaxial (right); b, capsule. 3, Rhytidiadelphus triquetrus (Hedw.) Warnst., habit; a, leaves, abaxial (above) and adaxial; b, capsule. 4, Rhytidiadelphus loreus (Hedw.) Warnst., habit; a, leaf; b, capsule. HYPNACEAE: 5, Hyocomium armoricum (Brid.) Wijk & Marg., habit; a, leaves; b, capsule.
From Berkeley (1863, Plate 9). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Rhytidiadelphus (with Campyliaceae, etc.: Berkeley. HYLOCOMIACEAE: 1, Rhytidiadelphus squarrosus (Hedw.) Warnst., procumbent habit form; a, abaxial leaf; b, capsule. CRATONEURACEAE: 6, Cratoneuron filicinum (Hedw.) Spruce, habit; a, leaves; b, capsule. CAMPYLIACEAE: 2, Sanionia uncinata (Hedw.) Loeske, habit; a, leaves; b, capsule (cf. Berkeley’s Plate 11,1). 3, Drepanocladus fluitans (Hedw.) Warnst., habit; a, leaves; b, capsule. 4, Scorpidium revolvens (Sw.) Hadenäs. HELODIACEAE: 5, Palustriella commutata (Hedw.) Ochyra, habit; a, leaf, abaxial; b, capsule. [4, Hypnum revolvens (Turn.) Warnst. (current generic assignment unknown), habit; a, leaves; b, capsule.]
From Berkeley (1863, Plate 10). The approximate 1 cm scale applies to the whole plant (habit) illustrations only. • Pleurozium, with Calliergonella and Pseudoscleropodium: Berkeley. HYLOCOMIACEAE: 2, Pleurozium schreberi (Brid.) Mitt., habit; a, adaxial and abaxial views of leaves; b, capsule. 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.
From Berkeley (1863, Plate 8). 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’.
