Pyrrhobryum
Dioicous, synoicous or rarely autoicous (not in Victoria). Asexual propagules absent. Tufts on logs, tree trunks or soil. Stems erect, simple or sparingly branched (not in Victoria), tomentose only at base or rarely throughout basal third (not in Victoria); central strand present. Leaves lanceolate to narrowly lanceolate or oblong (not in Victoria), sometimes falcate, becoming longer toward stem apex but otherwise monomorphic or rarely dimorphic toward stem apex (not in Victoria) with oblong-lanceolate and asymmetric dorsal leaves, and lanceolate and symmetric ventral leaves, arranged around stem and facing all directions or rarely becoming complanate toward stem apex (not in Victoria), erect-spreading to squarrose when moist, curled and twisted when dry; apex acute (not in Victoria) to acuminate; costa percurrent or excurrent (not in Victoria), toothed toward apex abaxially; margin serrate with paired teeth, plane, with at least a partially bistratose border but cells not elongate; laminal cells circular, irregular and isodiametric, quadrate or hexagonal, smooth; alar cells not differentiated. Pleurocarpous, perichaetia and perigonia at base or rarely at middle of stem (not in Victoria). Capsule inclined to horizontal, curved, cylindric to urceolate, with an annulus. Calyptra cucullate, smooth, glabrous. Operculum rostrate. Peristome double; endostome c. half height of exostome, with a high basal membrane; cilia present.
Around eight species shared between Central and South America and the islands of the Caribbean, Africa, Madagascar and the Mascarene Islands, south-east Asia eastwards from Sri Lanka north to Japan, and extending through Malesia to south-east Australia and throughout the larger islands of the Pacific; two species in Victoria.
Three former species of Pyrrhobryum, namely P. bifrarium (Hook.) Manuel, P. mnioides (Hook.) Manuel and P. vallis-gratiae (Hamp. In C.Müll.) Manuel were transferred to the previously monotypic Hymenodontopsis (Bell et al. 2007). This was done in response to a phylogeny of combined mitochondrial and chloroplast DNA sequences showing that these species were most closely related to H. stresemannii Herzog and that this genus is more closely related to Aulacomnium and the Aulacomniaceae than the Rhizogoniaceae (Bell et al. 2007). This division of the former Pyrrhobryum almost follows previous sectional division of the genus by Manuel (1980). Those species transferred to Hymenodontopsis were all placed in section Bifariella, distinguished from section Pyrrhobryum by non-basal perichaetia, a lack of subperichaetial innovation, and production of vegetative branches distally. However, distinction between Hymenodontopsis and Pyrrhobryum as defined by molecular characters, is currently obscured by P. dozyanum (Sande Lac.) Manuel that was previously placed in section Bifariella but according to the mitochondrial and chloroplast DNA phylogeny belongs to the Rhizogoniaceae, possibly close to Pyrrhobryum (Bell et al. 2007). Bell et al. (2007) retain this species within Pyrrhobryum but acknowledge that its phylogenetic position is ambiguous and requires confirmation. If P. dozyanum is not resolved among the other Pyrrhobryum species, its exclusion from that genus would allow easier morphological differentiation between Hymenodontopsis and Pyrrhobryum.
SpinningBell, N.E.; Quandt, D.; O’Brien, T.J.; Newton, A.E. (2007). Taxonomy and phylogeny in the earliest diverging pleurocarps: square holes and bifurcating pegs. The Bryologist 110: 533–560.
Manuel, M.G. (1980). Miscellanea bryological II. Classification of Rhizogonium Brid., Penzigiella hookeri Gangulee, and some nomina nuda. Cryptogamie Bryologie, Lichenologie 1: 67–72.
