Orthotrichum Moss

Orthotrichum rupestre Schleich. Crypt
Helvet. III. 24. 1806.
Orthotrichum Sturmii Hoppe & Hornsch. Flora 1: 341. 1818. (Nomen nudum.) Orthotrichum rupincola sensu Hook, in Drummond, Musci Am. 156. 1828. Not 0. rupincola Funck, 1820.
Plants in more or less dense tufts or cushions, olive-green above, brown to almost black below, rather stiff when dry; stems erect, 3-5 cm. long, or ascending and reaching 10 cm., more or less branched; leaves lanceolate, tapering to a narrowly obtuse or rarely acute apex, reaching
5 mm. in length, spreading to recurved when moist, keeled, the margins strongly recurved to near the apex; costa nearly or quite reaching the apex; median leaf-cells thick-walled, irregular or rounded above, 8-12 p in diameter, 1-2 times as long as broad, mostly unistratose, sometimes partially bistratose (or in forms partly in three layers), papillose, the papillae sometimes with two points; basal cells smooth, rectangular, linear in some of the upper leaves, 2-6 times as long as broad, the cell walls often more or less nodose and occasionally nearly as wide as the lumen, a small area of quadrate cells at the basal angles; autoicous; antheridial buds on axillary branches near the archegonial; capsules immersed to emergent, oblong to ovoid, light brown or yellowish, the urn 1.75-2.5 mm. long, the neck typically tapering but often short or almost wanting, scarcely contracted below the mouth when dry and empty except when very old, with 8 more or less conspicuous ridges when dry and empty, rarely with faint intermediate folds; calyptra hairy, with long spinulose hairs, plicate, covering most of the capsule; exothecial cells little differentiated, rather long; stomata superficial, usually near the base of the spore-sac, the bordering cells not radiating; annulus double, persistent, of two rows of cells; operculum rounded-conic, apiculate to short-rostrate; peristome-teeth 16, erect or spreading, at first often united in pairs, quite variable, solid or more or less perforate along the median line, smooth to faintly papillose, sometimes with faint sinuous lines, the segments well developed, of two rows of cells, to short and rudimentary or even wanting; spores ± 15 /x in diameter, papillose-roughened, maturing in spring.
Type locality: The Tyrol.
Distribution : On rocks and ledges containing little or no lime, in subalpine habitats ; the Rocky Mountains and westward, north to British Columbia, south to Texas; also in Europe, Asia, and northern Africa.