1. Pogonatum contortum (Bridel) Lesquereux, Mem. Calif. Acad. Sci. 1: 27. 1868.
Polytrichum contortum Bridel, J. Bot. (Schrader) 1800(1): 287. 1801
Plants medium-sized to large, in loose tufts or scattered, olive green to dark green. Stems 3-12 cm, erect, mostly simple. Leaves 5-9 mm, strongly crisped and contorted when dry, plane and broadly spreading when moist, loosely sheathing at base, linear-lanceolate, ending in a short spine; sheath not strongly differentiated, with gradually sloping shoulders, toothed nearly to the base with small sharp teeth oriented at right angles to the margin, hinge-tissue not differentiated; margins of blade thickened, (1-)2-stratose, coarsely serrate, scalloped, the serrations ending in a sharp-pointed, narrowly conical, reddish orange tooth cell; marginal lamina 1-stratose, to 6 cells wide; costa smooth adaxially or sharply toothed at the extreme tip; lamellae 40-48, entire in profile, 2-5 cells high, the marginal cells in section slightly larger but otherwise undifferentiated, thin-walled, smooth; sheath cells short rectangular; cells of the abaxial surface of blade 24-27 µm wide, irregularly quadrate to hexagonal, transversely elongate, firm-walled, with distinct corner thickenings, and a narrow median strip of cells short-rectangular and longitudinally elongate. Seta 3-5 cm. Capsule 2-3.5 mm, reddish brown to blackish brown, sometimes with 4 or more indistinct angles or ridges, erect to slightly inclined and asymmetric; exothecium finely scabrous, the cells distinctly papillate; peristome 300-350 µm, divided to 0.6, dark reddish orange with hyaline margins. Spores 8-13 um.
Soil, usually on clay banks; mostly at lower elevations, rarely to 1000 m; B.C.; Alaska, Calif., Oreg., Wash.; e Asia (Japan).
Pogonatum contortum is a handsome plant, growing in deep olive green tufts, rather wiry in appearance, with leaves strongly crisped and contorted when dry, short-cylindric, small, slightly asymmetrical capsules and a reddish hairy calyptra covering the capsule. When sterile and in the dry condition, it resembles Oligotrichum parallelum, but when moistened the leaves of P. contortum are more firm-textured, broadly lamellate, and toothed to the base.