Plants robust, 2–5 cm long, the shoots 5–6 mm wide, yellowish green to deep green. Stems densely tufted, branching occasionally, in section with a narrow central strand. Leaves close together on the stems, the bases slightly overlapping, patent, somewhat falcate when moist, the apices crisped and rolled up when dry, broadly lingulate to lingulate-lanceolate, 2.5–4.0 mm long, 0.8–1.3 mm wide; apex acute to obtuse and apiculate; laminae unistratose; margins crenulate below, sharply and irregularly dentate towards the apex; vaginant laminae up to 1/2–2/3 leaf length, half open; dorsal lamina rounded to the base, ending at the insertion or short-excurrent; costa of taxifolius-type, subpercurrent to percurrent, mostly ceasing 2–4 cells below the apex; cells of apical and dorsal laminae ±isodiametric, rounded-hexagonal, 12–18 μm wide, thick-walled, opaque, the 3 or 4 marginal rows more pellucid and thick-walled, forming a paler border.

Autoicous or ?dioicous. Perigonia axillary in clusters at about mid-stem. Perichaetia single in axils of leaves about mid-stem; perichaetial leaves reduced. Setae orange-brown, slender, sinuose, to 20 mm long. Capsules erect to horizontal, asymmetrical, 1.0–1.6 mm long; exothecial cells rectangular-hexagonal, thick-walled, 32–45 µm long, 11–25 μm wide, in c. 90–110 columns around the periphery at mid-capsule. Operculum to 1.5 mm long, curved-rostrate. Peristome of taxifolius-type; base of teeth 85–100 μm wide, the outer surface with low trabeculae and finely pitted lamellae; filaments slightly twisted, nodulose, with oblique striae between the nodules for most of their length. Calyptra smooth, cucullate. Spores 13–33 μm diameter, very finely and obscurely papillose, appearing smooth.

Native.

Occurs in Victoria and Tasmania. Also in New Zealand, Chile, Tierra del Fuego, Argentina. A widespread circumpolar species in temperate regions, in Europe north to Svalbard, the Faeroes, Iceland, Japan, China, the Azores, Madeira and North America.

Fissidens adianthoides Hedw., Sp. Musc. Frond. 157 (1801) Type: Europe; n.v., fide R.A.Pursell, Bryologist 89: 39 (1986a).

Taxonomic synonym

Fissidens major Mitt., J. Linn. Soc. Bot. 21: 559 (1885). Type: Europe; n.v.

Vic.: Surrey River, Cobboboonee State Forest, Gorae, A.C.Beauglehole 8171 (MEL 1059762).

Tas.: Nile River, Lymington, R.McLeod 750 (HO 75550, MEL); Lake St. Clair, L.Rodway (HO 75548); Wild Dog Plains, Central Highlands, A.Moscal 22827 (HO 300469); Meander River, A.Moscal 12477 (HO 108167); Prosser River, East Coast, A.Moscal 19612 (HO 77849).

When moist, the leaf tips are curved slightly towards the substratum and when dry the leaves are distinctly twisted and curled towards the ventral side of the shoots.

Sexuality of the Australian specimens is unclear as fertile material has not been found. Noguchi (1987) indicated the species is monoicous, while other authors, including Pursell (2007) and Beever et al. (2002), suggested dioicous, while Smith (2004) stated the species could be autoicous or dioicous.

Descriptive details of the sporophyte are from Smith (2004), Pursell (2007), and a British specimen [Hurstpierpoint, England, ex Hb. Mitten (HO 83670)]. The spores of the British specimen are 21–29 µm diam., and while appearing smooth they are actually very finely and obscurely papillose. The exothecial cells are very thick-walled and irregularly elongate-hexagonal to rhomboid or rectangular.

J.Beever, B.Malcolm & N.Malcolm, The Moss Genus Fissidens in New Zealand: an illustrated key. 12 (2002); A.J.E.Smith, The Moss Flora of Britain and Ireland 2nd edn, 257, figs 7–10 (2004).

Beever, J.E., Malcolm, W. & Malcolm, N. (2002). The Moss Genus Fissidens in New Zealand – an illustrated key. (Micro-Optics Press, Nelson).

de Winton, M.D. & Beever, J.E. (2004). Deep-water bryophyte records from New Zealand lakes. New Zealand J. Mar. Fresh. Res. 38: 329–340.

Noguchi, A. (1987). Illustrated Moss Flora of Japan. Part 1. (Hattori Botanical Laboratory, Nichinan).

Pursell, R.A. (2007). Fissidentaceae, Flora Neotropica Monograph 101. (Botanical Gardens Press, New York).

Smith, A.J.E. (2004). The Moss Flora of Britain and Ireland. 2nd edn. (Cambridge University Press, Cambridge).

Seppelt, R.D. & Stone, I.G. (2016). Australian Mosses Online 70. Fissidentaceae. Australian Biological Resources Study, Canberra. Version 16 June 2016. http://www.anbg.gov.au/abrs/Mosses_online/70_V2_Fissidentaceae.html

For more details about the history of this treatment see Fissidentaceae profile.