Plants 1–2 cm tall, green above, brown below, forming rough mats or short turfs. Stems creeping, with ascending upper parts, frequently branched when creeping; flagelliform branches occasionally present. Leaves erecto-patent to homomallously curved, the tips curled up when dry, subulate above the obovate basal part, 3.9–4.8 mm long, 0.6–1.0 mm wide, canaliculate, smooth; margin entire throughout or serrulate at the leaf shoulder, double-layered in the subula; border lacking; costa subpercurrent, abaxially smooth throughout or with a few minute teeth at the extreme apex; guide cells 7–9, with 2 layers of stereids on either side, adaxial and abaxial epidermis differentiated, consisting of cells with distinct lumina except at the base. Upper laminal cells conspicuously shorter than basal ones, oblate to isodiametric, rounded, 6–12 (–15) µm long, not pitted.

Perichaetial leaves subulate above the long sheathing basal part. Sporogones solitary; seta 13–26 mm long; capsules ovoid to ellipsoidal; peristome teeth entire to irregularly split or fenestrate, split to the base, very fragile.

Holomitrium perichaetiale can be distinguished from other mosses with spirally contorted leaves by its larger stature, and by the double-layered margin in the upper part of the leaves.

n = 10, fide Ramsay (1982: 312).

Native.

Occurs in eastern Queensland and New South Wales, eastern Victoria and Tasmania. Also known from Lord Howe Island, Norfolk Island and New Zealand. Grows in wet to dry forest or woodland, and on rock outcrops, tree and treefern trunks, and a canopy epiphyte in tropical rainforest.

Trichostomum perichaetiale Hook., Musci Exot. 1: 73 (1818); Holomitrium perichaetiale (Hook.) Brid., Bryol. Univ. 1: 227 (1826); Sprucea perichaetialis (Hook.) Hook.f. & Wilson, Fl. Antarct. 1: 128 (1844); Symblepharis perichaetialis (Hook.) Wilson, in J.D. Hooker, Fl. Nov.-Zel. 2: 60 (1854). Type: Dusky Bay, [South Island], New Zealand, 1791, A. Menzies; holo: BM.

Holomitrium muelleri Hampe, Linnaea 36: 514 (1870). Type: Rockingham Bay, Qld, F. Mueller; holo: BM.

Sclerodontium fraseri Mitt., Trans. & Proc. Roy. Soc. Victoria 19: 54 (1882); Leucoloma fraseri (Mitt.) Kindb., Enum. Bryin. Exot. 92 (1889); Dicnemoloma fraseri (Mitt.) Renauld, Essai Leucoloma 44 (1909). Type: s. loc., N.S.W., Fraser; syn: NY; Paramatta, N.S.W., W. Woolls; syn: NY.

Holomitrium hodgkinsoniae Müll.Hal., Hedwigia 36: 364 (1897). Type: Richmond River, N.S.W., 1879, Miss Hodgkinson; holo: B, destroyed.

Holomitrium hodgkinsoniae var. virescens Müll.Hal., Hedwigia 36: 365 (1897). Type: Greenwich, Sydney, N.S.W., June 1884, T. Whitelegge; holo: B, destroyed.

H.Streimann, The Mosses of Norfolk Island: 55, fig. 23 (2002); D. Meagher & B. Fuhrer, A Field Guide to the Mosses and Allied Plants of Southern Australia: 157 (2003).

Klazenga, N. (2012). Australian Mosses Online 33. Dicranaceae. (Australian Biological Resources Study: Canberra). Version 30 May 2012; https://www.anbg.gov.au/abrs/Mosses_online/33_Dicranaceae.html [Accessed July 2019]

Ramsay, H.P. (1986). Studies on Holomitrium perichaetiale (Hook.) Brid. (Dicranaceae: Bryopsida). Hikobia 9: 307–314.

Klazenga, N. (2012). Australian Mosses Online 33. Dicranaceae. (Australian Biological Resources Study: Canberra). Version 30 May 2012; https://www.anbg.gov.au/abrs/Mosses_online/33_Dicranaceae.html [Accessed July 2019]