Dioicous. Plants medium-sized, forming dense prostrate mats, yellow-green to pale green, or with some leaves reddish. Stems to 4 (–5) cm long, flattened; branches few. Leaves undulate and crisped when dry, ±straight when moist, spathulate, obovate to oval, 1.0–1.6 mm long, 0.5–1.0 mm wide; apex rounded, often with a small apiculus (occasionally to 50 μm long); margin entire, plane, often reflexed at the apex; costa extending to three-quarters of the leaf length, thin, c. 3 cells wide, c. 20 μm wide at the base. Laminal cells thin- to moderately thick-walled; upper cells irregularly quadrate to hexagonal, 8–17 (–20) × 7–14 μm; median cells irregularly hexagonal, 15–25 × 10–14 μm, smaller near the border; basal cells irregularly rectangular to hexagonal, to 37 (–63) × 13 μm; border of 2 or 3 rows of narrow elongate ±hyaline cells. Rhizoids smooth, often scattered and twisted, to 20 mm long, 15–30 μm wide; cells 100–180 μm long, obscure in older sections.

Perigonia gemmiform. Perichaetial leaves broadly elliptic, c. 1 mm long and 0.5 mm wide; costa absent or very weak. Laminal cells large, lax. Calyptra 2.0–2.5 mm long, mitrate, with a subscabrid apex. Seta reddish, 10–30 mm long, slightly twisted. Capsules reddish brown, horizontal to cernuous, 1.0–2.5 mm long; annulus narrow or lacking, adhering to the fragile 0.5–0.8 mm long operculum. Peristome teeth yellow, 290–350 μm long; basal membrane c. one-third the height of the teeth; endostome segments smooth, as high as the teeth, split between articulations. Spores granulose, 9–12 μm diameter.

The majority of collections and fertile specimens were from Tasmania, and most capsules were seen in November–April.

Known from south-eastern South Australia, eastern New South Wales, Australian Capital Territory, Victoria and Tasmania; common on wet rock faces and near waterfalls and on the lower stems of tree ferns, on logs and on ground; occurs in temperate rainforest and wet and dry sclerophyll forest. Also in Papua New Guinea, throughout New Zealand and on the Auckland Islands and Campbell Island.

Mniadelphus pulchellus Hampe, Synopsis Muscorum Frondosorum 2: 23 (1851); Distichophyllum pulchellum (Hampe) Mitt., Transactions and  Proceedings of the Royal Society of Victoria 19: 77 (1882). 
T: Auckland Islands, J.D.Hooker; syn: BM.

Taxonomic synonyms

Hookeria amblyophylla Hook.f. & Wilson, in J.D.Hooker, Flora Novae-Zelandiae 2: 123 (1854); Mniadelphus amblyophyllus (Hook.f. & Wilson) A.Jaeger, Bericht über die Thatigkeit der St. Gallischen Naturwissenschaftlichen Gesellschaft 1875–76: 320 (1877) [Ad. 2: 224]; Distichophyllum amblyophyllum (Hook.f. & Wilson) Mitt., Transactions and Proceedings of the Royal Society of Victoria 19: 77 (1882). T: Port Nicholson, North Island, New Zealand, A.Sinclair; Auckland, New Zealand, C.Knight; syn: BM.

Hookeria sinuosa Hook.f. & Wilson, in J.D.Hooker, Flora Tasmaniae 2: 219 (1859); Distichophyllum sinuosum (Hook.f. & Wilson) Mitt., Transactions and  Proceedings of the Royal Society of Victoria 19: 77 (1882). T: “Arthur’s Lakes”, Tas., R.C.Gunn; Hobart, Tas., A.F.Oldfield; syn: BM; isosyn: BM, HO.

Distichophyllum whiteleggeanum Müll.Hal., Hedwigia 41: 123 (1902); Mniadelphus whiteleggeanus (Müll.Hal.) Müll.Hal. ex M.Fleisch., Hedwigia 63: 214 (1922). T: Fitzroy Falls, Moss Vale, N.S.W., 8 Nov. 1884, T.Whitelegge; lecto: MEL, fide H.Streimann, Journal of the Hattori Botanical Laboratory 86: 107 (1999); isolecto: BM, NSW.

Mniadelphus subsinuosum Müll.Hal. ex M.Fleisch., Hedwigia 63: 214 (1922), nom. nud.; Distichophyllum subsinuosum Müll.Hal. ex M.Fleisch., Hedwigia 63: 214 (1922), nom. nud.

S.A.: Waterfall Gully, Adelaide, H.B.S.Womersley s.n. (MEL).

N.S.W.: New England Natl Park, 72 km E of Armidale, H.Streimann 47776 (Musci Austral. Exs. 114) (CANB); Stoney Ck, 34 km SE of Nowra, H.Streimann 45231 (CANB, NY).

A.C.T.: Brindabella Ra., 32 km SW of Canberra, H.Streimann 5268 (CANB, L).

Vic.: Result Ck, Bendoc–Orbost road, 13 km SW of Bendoc, H.Streimann 36525 (CANB, NY).

Tas.: Lune River Rd, 5 km SW of Lune, J.A.Curnow 2708 (B, CANB, HO, NY).

G.O.K.Sainsbury, Bulletin of the Royal Society of New Zealand 5: 400 (1955); D.J.Catcheside, Mosses of South Australia 300, fig. 181 (1980); H.Streimann, Journal of the Hattori Botanical Laboratory 86: 108, fig. 11 (1999); D.Meagher & B.Fuhrer, A Field Guide to the Mosses and Allied Plants of Southern Australia 37 (2003).

Streimann, H. (2012). Australian Mosses Online 11. Hookeriaceae: [Distichophyllum]. Australian Biological Resources Study, Canberra. Version 19 April 2012