Orthotrichum pulchellum var. groutii E. Lawton

Plants to 1.6 cm. Stem leaves crisped-flexuose when dry, narrowly lanceolate to linear-lanceolate, 1.6-3.2 mm; margins recurved to near apex, entire; apex sharply acute; basal laminal cells rectangular, walls thick, not nodose; distal cells 8-14 µm, 1-stratose, papillae 1-2 per cell, conic, small. Specialized asexual reproduction absent. Sexual condition gonioautoicous. Seta (0.8-) 1-3(-3.5) mm. Capsule exserted or sometimes 1/2 emergent, oblong-cylindric, 0.9-2.1 mm, strongly 8-ribbed entire length; stomata immersed, ; peristome double; prostome absent; exostome teeth 16, rarely connate in 8 pairs, erect when mature, reflexed when old, irregularly papillose-reticulate; endostome segments 16, well developed, of 1 row of cells, finely roughened. Calyptra oblong-conic to conic, smooth, naked. Spores 12-24 µm.

Trunks, branches, twigs of deciduous and coniferous trees; low to moderate elevations (0-1000 m); B.C.; Alaska, Calif., Idaho, Oreg., Wash.

Orthotrichum pulchellum is distinguished from all species of Ulota by its glabrous calyptrae and immersed stomata, and from O. consimile by the 16 reddish exostome teeth that are papillose-reticulate with slender, high papillae, and stomata always located at or beyond mid capsule. Also, plants of O. pulchellum are rarely longer than 1 cm, and capsules are usually barely exserted and oblong-cylindric.