Lanceolateleaf Rock Moss

Orthotrichum speciosum Nees in Sturm, Deuts. Fl. Crypt, 5(17): 5. 1819.
Orthotrichum speciosum var. poly car pum Lesq. & James, Man. 169. 1884. Orthotrichum Rauei Aust. Bull. Torrey Club 6: 343. 1879.
Plants in tufts, loose to dense, green to yellow-green above, 1-4 cm. high, branching; leaves loosely imbricate when dry, oblong-lanceolate to elongate-lanceolate, acute to very slenderly acuminate, keeled, reaching 3-4 mm. long, the margins recurved nearly to the apex except in young or perichaetial leaves; costa nearly or quite percurrent; basal leaf -cells quadrate at the margins, near the costa long-rectangular, the longitudinal walls becoming very thick and nodose with age, gradually merging into the upper rounded or oblong incrassate cells, which are 12-15 y. in diameter (18-20 n according to Limpricht), strongly papillose with one or more strong, sharp, simple or bifid papillae; autoicous; seta 1.5-2 mm. long; capsules greenish, changing to light yellow, nearly or quite exserted, with a long neck of thin tissue, cylindric to oblong-ovoid when dry, nearly smooth until empty, then slightly narrowed under the mouth and lightly plicate the whole length when old, the urn about 2 mm. long with 8 bands, clearly indicated by bands of differentiated exothecial cells with thicker walls; calyptra hairy; stomata superficial, surrounded by shorter cells; annulus present, below it 3-5 rows of small, incrassate, rounded cells; operculum conic with a beak equal to its diameter; peristometeeth 8, geminate, rarely separating, strongly papillose, often perforate, when dry typically revolute with the tips touching the outer wall of the capsule, the segments 8, well developed, nearly as long as the teeth, rather irregular in outline, often appendiculate, of two rows of cells; spores 15-25 /x in diameter, papillose, usually maturing in early summer.
Type locality: Germany.
Distribution: Mostly on trees, sometimes on non-calcareous rocks; California to Alaska; Europe; Asia; Africa.