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BFNA | Family List | BFNA Vol. 1 | Polytrichaceae | Pogonatum

Pogonatum contortum (Bridel) Lesquereux, Mem. Calif. Acad. Sci. 1: 27. 1868.

  • Polytrichum contortum Bridel

    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; lamina within the margins 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;l mostly at lower elevations, rarely to 1000 m; B.C.; se Alaska, Calif., Ore., Wash.; 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.


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