Plants loosely or densely tufted, 3.5–12.0 mm tall, yellow to olive-green above, brown to black below. Leaves appressed-flexuose when dry, ovate-lanceolate to lanceolate, 1.8–4.1 mm long; apex rounded-acute, acute or acuminate; margin recurved, entire, rarely dentate apically; upper laminal cells isodiametric, 6.5–20.0 µm wide, thick-walled, each with 2–4 low mostly unbranched papillae; basal laminal cells rectangular, 15–90 × c. 9.5 µm, usually thin-walled, smooth, without pores. Gemmae 5–7 cells long.

Calyptra conical, plicate, split, with long hairs. Capsules immersed to emergent, sometimes recurved when dry, narrowly cylindrical, deeply 8-ribbed and constricted below mouth when dry; stomata immersed. Peristome double; exostome teeth 8, recurved, papillose; endostome segments 8, well developed, narrow. Spores 6–21 µm diameter.

n = 11 (10 + m), cited in H.P. Ramsay, Austral. J. Bot. 22: 308–309 (1974), as Orthotrichum tasmanicum; H.P. Ramsay, J. Hattori Bot. Lab. 74: 188 (1993).

Native.

Found in New Zealand and South America. In Australia it occurs in southeastern New South Wales, the Australian Capital Territory and Victoria.

This species is primarily epiphytic, but it is also found on calcareous and non-calcareous rocks up to 1500 m.

Orthotrichum assimile Müll.Hal., Syn. Musc. Frond. 1: 704 (1849). Type: "Chile: Pöppig"; lecto: Chile, E.F.Poppig s.n., H, designated by J. Lewinsky, Lindbergia 10: 73 (1984).

Taxonomic synonym

Orthotrichum acroblepharis Müll.Hal., Hedwigia 37: 136 (1898). Type: "Australia, Victoria, Upper Oven's River: Mstrs. Mc.Cann 1882 in Hb. Melbourne"; holo: upper Ovens R., Vic., A.McCann s.n., ?MEL; iso: JE.

Misapplied names

Orthotrichum longithecum auct. non R.Br.ter.: J. Lewinsky, J. Hattori Bot. Lab. 56: 436 (1984).

Orthotrichum tasmanicum auct. non Hook.f. & Wilson: H.P. Ramsay, Austral. J. Bot. 22: 308–309 (1974).

Orthotrichum alpestre auct. non Hornsch.: G.A.M. Scott & I.G. Stone, The Mosses of Southern Australia 228 (1976).

N.S.W.: Mount Canobolas, H. Streimann 9184 (CANB); Yarrangobilly Caves, H.P. Ramsay 5/66 (NSW); Island Bend, H. Streimann 4020 (CANB).

A.C.T.: Naas Creek, H. Streimann 2293 (CANB).

Vic.: Buchan Caves, J. Lewinsky 1840 (C).

J. Lewinsky, J. Hattori Bot. Lab. 56: 436, fig. 32; 438, fig. 33 (1984), as Orthotrichum longithecum.

J. Lewinsky-Haapasaari  & H.P. Ramsay (2012), Australian Mosses Online 47. Orthotrichaceae: Orthotrichum. Australian Biological Resources Study, Canberra. Version16 June 2012. 

First published as: J.Lewinsky-Haapasaari  & H.P. Ramsay (2006), Orthotrichaceae: Orthotrichum, Fl. Australia 51: 187–244.