Dioicous, synoicous or, rarely, autoicous. Plants mostly tufted, usually green or yellowish, sometimes with pink or red colouration. Stems erect, sometimes arising from stoloniferous primary stems (Rhodobryum), simple or branched by subperichaetial innovations, sometimes radiculose below with coloured papillose rhizoids. Leaves in many rows, usually small and remote below, larger and crowded above, frequently in comal tufts or rosulate, usually erect to erect-spreading, rarely complanate, sometimes twisted or crisped when dry, lanceolate to ovate, rarely triangular, obovate or spathulate, mostly acute, sometimes long-acuminate or piliferous, frequently bordered, unistratose; border rarely bistratose; margin smooth or denticulate to serrate; costa single, well developed, often excurrent, sometimes with a stereid band in cross-section. Laminal cells smooth, prosenchymatous, typically transparent, relatively large; upper cells rhomboidal-hexagonal to rhomboidal or, less frequently, linear or vermicular, rectangular or sometimes short-rectangular or quadrate towards base. Gemmae frequently produced.

Perichaetia and perigonia mostly terminal; perichaetia rarely on short basal branches; perichaetial leaves not well differentiated. Calyptra cucullate, smooth, usually shed early in capsule development. Setae elongate, usually solitary, rarely multiple, erect or ± curved near tip. Capsules mostly inclined to pendent or nutant, occasionally curved, rarely erect, usually symmetrical, almost always smooth, ovoid, pyriform or oblong-cylindrical, rarely subglobose, with a well-developed neck tapered to the seta and wrinkled when dry; annulus usually present, large and revolute; operculum convex to short-conical, umbonate or apiculate, rarely short-rostrate; stomata numerous, restricted to neck, mostly superficial. Peristome usually present, diplolepidous, double, rarely single; exostome teeth 16, mostly lanceolate and slender-pointed, often bordered, prominently trabeculate, papillose on the outer surface; endostome segments typically 16, alternating with teeth, hyaline or yellow, keeled, arising from a generally well-developed smooth basal membrane; cilia delicate, 1–3. Spores smooth to finely papillose, 8–50 µm diam. 

n = 10, 11 (10 + m), 20, 30 for Australian species, fide Ramsay & Spence (1996); see also Fritsch (1991).

The cosmopolitan Bryaceae includes 15 genera and up to 600 species and is found in most habitats, from running streams to dry deserts and from the polar regions to tropical latitudes. It is most common in open situations, less so in dense forest. Species usually grow on earth, rock or rotting wood, less commonly as an epiphyte.

Spence & Ramsay (2006: 274) reported that the family was represented in Australia by 8 genera and 54 species; in Spence & Ramsay (2019) they recognise 11 genera occurring in Australia.

Bryaceae Schwägr., in C.L. von Willdenow, Sp. Pl. 5(2): 47 (1830). Type: Bryum Hedw.

The family traditionally consisted of four subfamilies: Orthodontoideae, Mielichhoferioideae, Pohlioideae, Bryoideae. This classification placed particular emphasis on the sporophyte, especially the position of the gametangia, capsule orientation, and reduction in the peristome. Recent and current studies are redrawing subfamily relationships more along gametophytic lines (Cox & Hedderson 2003, Pederson et al. 2003). Peristome reduction appears to have occurred independently several times, and is probably not the best indicator of phylogenetic affinities. Most problems lie in the large polyphyletic genera Bryum and Brachymenium which require a re-assessment of generic and subfamily limits. Pohlia, Mniobryum and Schizymenium apparently share a more recent ancestor with Mnium (Mniaceae) and related genera than with genera in the Bryaceae subfam. Bryoideae. Leptobryum belongs in the Meesiaceae with other genera having a well-developed, sterile capsule neck. Orthodontium, long enigmatic within the Bryaceae (and placed in its own subfamily by Brotherus), is positioned by molecular investigations in the resurrected family Orthodontiaceae (Buck & Goffinet 2000). The inclusion of Pleurophascum in the family (Buck & Goffinet 2002) was due to misreading the rps4 in the matrix, and it has now been excluded and returned to its own family Pleurophascaceae (Goffinet & Buck 2004). The Bryaceae s. str. thus includes mostly genera with heterogenous laminal areolation and comparatively short cells and typically bordered leaves (subfam. Bryoideae sensu Brotherus).

Earlier studies of Australian Bryacaeae (Ochi 1970, 1972, 1973, 1984, 1988) were based entirely on herbarium specimens, while more recent investigations (Spence 1996, 2005; Spence & Ramsay 1996, 1999, 2005) have also benefited from extensive field studies by J.R. Spence. This treatment represents the first major revision in more than 100 years. Groups of species are described based primarily on features of the gametophyte, which appears to provide a relatively stable basis for delimitation of genera in the Bryaceae. A new genus Rosulabryum was described for the rosulate species (Spence 1996). New concepts are included here for Brachymenium, and Bryum has been restricted to those species formerly placed in Anomobryum (Spence & Ramsay 2002). The genus Ptychostomum has been resurrected for species previously placed in Bryum sect. Cladodium (Spence 2005). Two new genera, Ochiobryum and Gemmabryum, have also been described by Spence & Ramsay (2005).

[The family Bryaceae was revised for the bryophyte Flora of Australia Volume 51 by Spence and Ramsay (2006) and later ?updated in Australian Mosses Online (Spence & Ramsay 2012). Since then there have been further revisions, see Spence & Ramsay (2013, 2019), Spence (2014) - P.G. Kodela, 12 December 2023.]

The Bryaceae are best characterised by the capsule shape: elongate with a well-formed neck that tapers to the seta. The capsules are mostly pyriform and nodding. The perfect double peristome with alternating exostome and endostome is variously reduced in a few genera. It resembles that of the Mniaceae and Aulacomniaceae as well as hypnoid pleurocarps. Chromosome numbers are based on x =10 (perhaps 5) with considerable intra- and interspecific polyploidy and aneuploidy.

In the absence of sporophytes, some members of the Bryaceae are notoriously difficult to identify to species or even genus. However, details of laminal areolation can often place a specimen in the appropriate genus or section reasonably quickly. Most species conform to one of three basic patterns of areolation in older leaves as follows:

a. Pohlioid: with laminal cells elongate and linear to hexagonal and ±uniform from near the leaf tip to the base, e.g. Ochiobryum and Plagiobryum.

b. Rhodobryoid: with upper laminal cells rhomboidal to hexagonal, gradually changing to more elongate and rectangular in the lower part of the leaf, e.g. Brachymenium, Ptychostomum, Rhodobryum and Rosulabryum.

c. Anomobryoid: in which the upper laminal cells are elongate and linear to hexagonal, with the lower cells abruptly quadrate to short-rectangular and often broader, e.g. Bryum and Gemmabryum.

In addition to these laminal cell patterns, vegetative propagules such as filamentous gemmae, bulbils, rhizoidal tubers and stem tubers can facilitate identification, especially of sterile collections. It is important to look at older leaves when using a key as the current year’s growth and sterile innovations often produce atypical leaves.

Buck, W.R. & Goffinet, B. (2000). Morphology and classification and mosses, in Shaw, J. & Goffinet, B. (eds), Bryophyte Biology, pp. 71–123. (Cambridge University Press: Cambridge).

Catcheside, D.G. (1980). Mosses of South Australia, pp. 248–278. (South Australian Govt. Printing: Adelaide).

Cox, C.J. & Hedderson, T.A.J. (2003). Phylogenetic relationships within the moss family Bryaceae based on chloroplast DNA evidence. Journal of Bryology 25: 31–40.

Fritsch, R. (1991). Index to bryophyte chromosome counts. Bryophytorum Bibliotheca 40: 1–352.

Goffinet, B. & Buck, W.R. (2004). Systematics of the Bryophyta (mosses), from molecules to a revised classification, in Goffinet, B., Hollowell, V. & Magill, R. (eds), Molecular Systematics of Bryophytes, pp. 205–239. (Missouri Botanical Garden Press: St. Louis).

Holyoak, D.T. (2021). European Bryaceae: A guide to the species of the moss family Bryaceae in Western & Central Europe and Macaronesia. (Pisces Publications: Newbury, U.K.).

Ochi, H. (1970). A revision of the subfamily Bryoideae in Australia, Tasmania, New Zealand and adjacent islands. Journal of the Faculty of Education: Tottori University: Natural Science 21: 7–67.

Ochi, H. (1972). Some problems of distributional patterns and speciation in the regions including Eurasia, Africa and Oceania. The Journal of the Hattori Botanical Laboratory 35: 217–223.

Ochi, H. (1973). Supplement to the subfamily Bryoideae (Musci) in Australia and New Zealand. Hikobia 6: 217–223.

Ochi, H. (1982). A phytogeographical consideration of Australasian Bryoideae in relation to those in other continents. The Journal of the Hattori Botanical Laboratory 52: 65–73.

Ochi, H. (1985). An annotated list of mosses of the subfamily Bryoideae in South, Southeast and East Asia. Journal of the Faculty of Education: Tottori University: Natural Science 34(2): 41–96.

Ochi, H. (1988). Recent work on a worldwide revision of the Bryoideae (Musci). Bryological Times 48: 1–3.

Ochi, H. (1992). A revised infrageneric classification of the genus Bryum and related genera (Bryaceae, Musci). Bryobrothera 1: 231–244.

Ochi, H. & Streimann, H. (1987). Miscellaneous additions of bryaceous mosses (Bryaceae) to the floras of Papua New Guinea and Australia. Memoirs of the New York Botanical Garden 45: 615–617.

Pederson, N. (2005). Validation of Imbibryum (Bryaceae). Bryologist 108: 449.

Pedersen, N., Cox, C.J. & Hedenäs, L. (2003). Phylogeny of the moss family Bryaceae inferred from chloroplast DNA sequences and morphology. Systematic Botany 28: 471–482.

Pedersen, N. & Hedenäs, L. (2005). Taxonomic and nomenclatural implications of phylogenetic studies of the Bryaceae based on molecular data and morphology. Bryologist 108: 123–128.

Pedersen, N., Holyoak, D.T. & Newton, A.E. (2007). Systematics and morphological evolution within the moss Bryaceae: a comparison between parsimony and Bayesian methods for the reconstruction of ancestral states. Molecular Phylogenetics and Evolution 43: 891–907.

Ramsay, H.P. & Spence, J.R. (1996a). New chromosome data on Australasian Bryaceae. The Journal of the Hattori Botanical Laboratory 80: 151–170.

Ramsay, H.P. & Spence, J.R. (1996b). Chromosome studies on Australasian Bryaceae. The Journal of the Hattori Botanical Laboratory 80: 251–270.

Scott, G.A.M. & Stone, I.G. (1976). The Mosses of Southern Australia, pp. 269–303.

Spence, J.R. (1987). A proposed reclassification of Bryum, Anomobryum and Brachymenium (Musci, Bryaceae). Journal of Bryology 14: 659–676.

Spence, J.R. (1996). Rosulabryum genus novum. Bryologist 99: 221–225.

Spence, J.R. (2004). A preliminary treatment of the Bryaceae of the Bryophyte Flora of North America region. Evansia 21: 1–16.

Spence, J.R. (2005). New genera and combinations in the Bryaceae (Bryales, Musci) for North America. Phytologia 87(1): 15–28.

Spence, J.R. (2007). Nomenclatural changes in Bryaceae (Bryopsida) for North America II. Phytologia 89(1): 110–114.

Spence, J.R. (2009). Nomenclatural changes in Bryaceae (Bryopsida) for North America III. Phytologia 91(3): 493–499.

Spence, J.R. (2014). Bryaceae Schwägr., in Zander, R.H. (ed.), Bryophyte Flora of North America Volume 28. (Flora of North America Editorial Committee, Oxford University Press: New York).

Spence, J.R. & Ramsay, H.P. (1996). Biogeography of the subfamily Bryoideae (Bryaceae, Musci) in north-eastern Queensland. Australian Systematic Botany 9: 185–192.

Spence, J.R. & Ramsay, H.P. (1996). New and interesting species of Bryaceae from Australia. Journal of the Adelaide Botanic Gardens 17: 107–118.

Spence, J.R. & Ramsay, H.P. (1999). Three new species of Rosulabryum in Australia. Telopea 8(3): 325–335.

Spence, J.R. & Ramsay, H.P. (1999). (1435) Proposal to conserve the name Bryum (Musci, Bryaceae) with a conserved type. Taxon 48: 827–828.

Spence, J.R. & Ramsay, H.P. (2002). The genus Anomobryum Schimp. (Bryopsida, Bryaceae) in Australia. Telopea 9(4): 777–792.

Spence, J.R. & Ramsay, H.P. (2005). New genera and combinations in the Bryaceae (Bryales, Musci) for Australia. Phytologia 87(2): 61–71.

Spence, J.R. & Ramsay, H.P. (2006). Bryaceae, in McCarthy, P.M. (ed.), Flora of Australia 51: 274–310, 319–348, 411–412. (Australian Biological Resources Study: Canberra / CSIRO Publishing: Melbourne).

Spence, J.R. & Ramsay, H.P. (2012). Australian Mosses Online 50. Bryaceae. (Australian Biological Resources Study: Canberra). Version 21 June 2012;
https://www.anbg.gov.au/abrs/Mosses_online/50_Bryaceae.html

Spence, J.R. & Ramsay, H.P. (2013). Additions to and nomenclatural changes in the Bryaceae (Bryopsida) in Australia. Telopea 15: 143–148.

Spence, J.R. & Ramsay, H.P. (2019). Revised keys and additions to the Australian Bryaceae (Bryopsida). Telopea 22: 99–134.

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Revised edition, 12 December 2023. Based on Spence & Ramsay (2006, 2012).