Plants small to medium. Stems simple to fastigiate, red to red-brown, to c. 20 mm tall. Leaves distinctly 5-ranked, lanceolate to linear-lanceolate, acuminate, 1.75–2.40 mm long,
0.33–0.56 mm wide; margin recurved and denticulate above; costa excurrent to long-excurrent, toothed dorsally by projecting cell ends, poorly defined due to the presence of multistratose costal wings that extend to within 5–9 cells of the margin, occupying c. two-thirds of the leaf base; laminal cells poorly defined, rectangular, 30–60 × 4–10 µm, prorate; lower cells longer.

Perigonia and perichaetia terminal. Perichaeital leaves similar to stem leaves but with a markedly thinner costa. Setae c. 20 mm long. Capsules inclined to horizontal, globose to ovoid, sulcate. Peristome single; exostome teeth red, long-triangular-lanceolate, trabeculate, smooth, joined at the apices. Spores subglobose to reniform, 58–60 µm diameter.

Native.

It has been reported from Australian Capital Territory, Victoria and Tasmania, but I have only seen specimens from Tasmania, and I consider mainland records of C. pentastichum doubtful due to previous confusion with C. pusillum. Conostomum pentastichum is also found in New Zealand, Macquarie Island, Auckland Island, Campbell Island, South America and southern Africa.

This species is found on soil in alpine and subalpine regions.

Bartramia pentasticha Brid., Muscol. Recent. 2(3): 134 (1803); Conostomum pentastichum (Brid.) Lindb., öfvers. Förh. Kongl. Svenska Vetensk.-Akad. 20: 392 (1863).
Type: ad stretum Magellanicum, P.Commerson, ex Herb. Swartz; holo: BM n.v., fide A.J.Fife, New Zealand J. Bot. 609 (1998); B? n.v., fide J.-P.Frahm et al., Trop. Bryol. 106 (1996).

Taxonomic synonyms

Conostomum australe Sw., J. Bot. (Schrader) 1(3): 31 (1806); Philonotis australis (Sw.) Mitt., J. Proc. Linn. Soc., Bot. 4: 81 (1860); Bartramia australis (Sw.) Mitt., J. Linn. Soc., Bot. 12: 267 (1869).
Type: as for Bartramia pentasticha.

Tas.: Zig Zag Track, Mt Wellington, A.V.Ratkowsky H171 (CANB); Lake Fenton, Mount Field Natl Park, D.H.Norris 28545 (CANB).

Frahm et al. (1996) included C. giganteum in the Australian flora, but Fife (1998) synonymised it with C. pentastichum. A duplicate of the specimen cited by Frahm et al. (H.Streimann 4371, CANB) is a large C. pusillum. It has been included in the Australian flora as a misapplied name under that species.

A.J.Fife, New Zealand J. Bot. 609, fig. 3 (1998); J.Beever, K.W.Allison & J.Child, Mosses of New Zealand, 2nd edn 104, fig. 46 (1992); R.D.Seppelt, The Moss Flora of Macquarie Island 73, fig. 29 (2004).

Fife, A.J. (1998). A synopsis of the New Zealand representatives of Conostomum (Musci: Bartramiaceae). New Zealand Journal of Botany 36: 605–615.

Frahm, J-P., Börner, H., Streiber, N., Wallau, B. & Weitkus, S. (1996). Revision der Gattung Conostomum (Musci, Bartramiaceae). Tropical Bryology 12: 97–114.

Gilmore, S.R. (2012). Australian Mosses Online 42. Bartramiaceae. Australian Biological Resources Study, Canberra. Version 9 June 2012. http://www.anbg.gov.au/abrs/Mosses_online/42_Bartramiaceae.html

First published as: Gilmore, S.R. (2006). Bartramiaceae, in McCarthy, P.M (ed.) Flora of Australia 51: 248–270. (Australian Biological Resources Study, Canberra & CSIRO Publishing, Melbourne.)