Clades:
Hypnales,
Bryidae,
Bryanae,
Bryophyta,
Plants.
Region: nearly worldwide, most diverse in subtropics and tropics.
Genera: 60; ± 600 species.
BotanyMoss: small to large, lax to dense, in tufts or mats, dark green, yellow-green, golden green, or orange, sometimes reddish-brown or nearly black, often lustrous.
Stems: creeping, suberect, or erect, occasionally complanate-foliate or julaceous, irregularly branched to regularly 1-pinnate or 2-pinnate; hyalodermis 1-stratose or absent, central strand present or absent; pseudoparaphyllia filamentous, foliose, or absent; rhizoids often in clusters proximal to juncture of leaves on adaxial surface of stems and branches, smooth or papillose; axillary hair basal-cells 1–2 (–4), short, brown, distal cells 1–several, elongate, hyaline.
Leaves: stem and branch similar or less commonly differentiated, straight to homomallous, often falcate-secund, usually ovatelanceolate, often asymmetric, sometimes linear, lanceolate, or triangular, occasionally plicate; base sometimes decurrent; margins often plane, occasionally recurved proximally or throughout, entire or toothed; apex obtuse to acuminate; costa double, short, to obscure or ecostate; alar cells usually differentiated, often quadrate to short-rectangular, sometimes enlarged and inflated, pigmented or similar in color to other cells, excavate or plane; medial and distal laminal cells linear, hexagonal, or elongate-sinuate, smooth, sometimes prorulose at distal ends on abaxial surface.
Specialized asexual reproduction sometimes by leafy propagula or filamentous gemmae clustered in leaf-axils. Sexual condition autoicous, dioicous, or phyllodioicous. Seta elongate, smooth (occasionally scabrous near capsule in Ctenidium).
Capsule inclined, horizontal, or sometimes erect, cylindric or ovoid, usually smooth, often constricted below mouth when dry and empty; operculum conic or rostrate; peristome usually double; exostome teeth 16, external surface cross striate basally, papillose distally, sometimes bordered, internal surface often trabeculate; endostome usually free, sometimes fused to exostome, basal membrane high or rarely low, segments 16, cilia 1–3, nodose, rarely rudimentary or absent.
Calyptra: cucullate, smooth (weakly prorulose distally in Ctenidium), naked or rarely hairy. Spores spheric to ovoid, usually finely papillose, rarely smooth.
TaxonomyHypnaceae once held a high proportion of pleurocarpous species, with about 150 genera. But recent phylogentic research has shown that the family is far from monophyletic. As genera are monographed, they are often placed in other families. The distinctive hypnoid peristome has been used as a significant feature, but this is not entirely reliable.
Genera: Acritodon, Andoa, Austrohondaella, Bardunovia, Breidleria, Bryocrumia, Buckiella, Callicladium, Calliergonella, Campylophyllopsis, Campylophyllum, Caribaeohypnum, Chryso-hypnum, Crepidophyllum, Ctenidiadelphus, Cyathothecium, Dacryophyllum, Ectropotheciella, Ectropotheciopsis, Ectropothecium, Elharveya, Elmeriobryum, Entodontella, Eurohypnum, Foreauella, Gammiella, Giraldiella, Gollania, Hageniella, Herzogiella, Homomallium, Hondaella, Horridohypnum, Hyocomium, Hypnum, Irelandia, Isopterygiopsis, Leiodontium, Leptoischyrodon, Macrothamniella, Mahua, Microctenidium, Mittenothamnium, Nanothecium, Orthothecium, Phyllodon, Plagiotheciopsis, Platydictya, Platygyriella, Podperaea, Pseudohypnella, Pseudotaxiphyllum, Ptilium, Pylaisia, Rhacopilopsis, Rhizohypnella, Sclerohypnum, Stenotheciopsis, Stereodon, Stereodontopsis, Syringothecium, Taxiphyllopsis, Taxiphyllum, Vesicularia, Wijkiella