Bartramia halleriana Hedwig, Sp. Musc. p. 164. 1801.
Plants robust, green or yellowish brown, in tight to lax tufts. Stems to 15 cm. Leaves crisped when dry, erect-spreading when moist, sometimes secund, narrowly lanceolate, long-subulate, base laxly sheathing; margins revolute from shoulders to high in the acumen, entire proximally, denticulate in shoulders, spinose-dentate above; costa excurrent, rough abaxially in the distal portion, spinose in excurrent tip; basal laminal cells thin-walled from costa to margin; median and distal cells 5--12 × 4(--10) mm. Sexual condition autoicous or synoicous. Seta curved, 2(--8) mm, often 2 or 3 per perichaetium. Capsule subglobose to pyriform, asymmetrical, furrowed, 1.5(--2.5) mm, persisting on older sections of stems, somewhat hidden by leaves; operculum conic convex; peristome double; teeth lanceolate, 500--550 µm, strongly transversely barred, reddish brown, granulose proximally, papillose above; endostome with high basal membrane, segments striate papillose, slightly shorter than teeth, cilia present, weakly developed. Spores 15--24 µm, warty papillose.
Capsules mature June--Sept. Crevices of shaded cliffs and on rock outcrops in humid forests; 200--500 m; Alta, B.C.; Europe; Asia; s South America; Australia (Tasmania); Pacific Islands (Hawaii, New Zealand).
Vegetatively, this species is quite similar to robust forms of Bartramia pomiformis; the short, curved seta equaling or slightly longer than the capsule, however, is distinctive.