Orthotrichum Moss

Orthotrichum diaphanum Brid. Muse
Recent. 2 2 : 29. 1801.
Orthotrichum canum Mitt. Jour. Linn. Soc. 8: 26. 1864.
Tufts small, dense, 0.5-1 cm. high, grayish-green by reason of the hyaline leaf-tips, sparingly branched; leaves loosely imbricate, oblong-lanceolate to oblong-elliptic, sometimes bearing septate brood-bodies, mostly ending in a narrow, hyaline, rough hair-point which is longer in the upper and perichaetial leaves, about 2 mm. long, the margins revolute; costa ending in or below the apex; upper leaf -cells having walls little thickened, irregularly roundedhexagonal, 14-20 /x in diameter, bearing simple papillae or nearly smooth, the basal cells rectangular, smooth, less dense, shorter on the margins; monoicous; seta short, =b 0.5 mm, long; capsules oblong-elliptic, immersed to emergent, 1.5-2 mm. long, light-colored, abruptly narrowed to the seta, smooth to faintly ribbed when dry (said to be strongly ribbed when old in European plants), then subcylindric; calyptra covering two-thirds of the capsule, nearly or quite naked; exothecial cells rather thinwalled, differentiated; stomata immersed, near the middle of the capsule; annulus present; operculum conic-rostellate; peristome double, the outer of 16 narrowly lanceolate teeth which are spreading to recurved when dry, sometimes split at the apex, strongly papillose with high, narrow papillae, reaching 0.3 mm. in length in European plants but mostly about 0.2 mm. in American, the segments 16, filiform, only a little shorter than the teeth and similarly papillose; spores rough, maturing in late winter and early spring.
Type locality: Europe.
Distribution: On the base of trees; Texas, Arizona, and Colorado; Mexico; Europe; Asia;