7. Orthotrichum consimile Mitten, J. Linn. Soc., Bot. 8: 24. 1864.
Orthotrichum columbicum Mitten; O. hendersonii Renault & Cardot; O. pulchellum var. columbicum (Mitten) Grout; O. pulchellum var. leucodon Venturi; O. pulchellum var. longipes Lesquereux & James; O. pulchellum var. productipes Renault & Cardot; O. pulchellum subsp. ulotiforme (Renault & Cardot) Kindberg; O. ulotiforme Renault & Cardot
Plants 8-20 cm. Stem leaves erect, crisped-flexuose when dry, linear-lanceolate, 2-3.2 mm; margins recurved to near apex, sometimes reflexed beyond, entire; apex acuminate (sometimes bluntly so) or acute; basal laminal cells linear-elongate to long-rectangular, walls thick, not nodose; distal cells 7-11 µm, 1-stratose, smooth or papillae 1 or 2 per cell, blunt, lo w. Specialized asexual reproduction absent. Sexual condition gonioautoicous. Seta (1.5-)2.5-6 mm. Capsule exserted to long-exserted, ovate-oblong when young, elliptic-cylindric when old, 2.5-6 mm, 8-ribbed entire length; stomata immersed, ; peristome double; prostome absent; exostome teeth 8, erect when mature, reflexed when old, external surface very finely and densely papillose, internal surface finely striate; endostome segments usually 16, rarely 8 (sometimes 8 long, 8 short), not well developed, of 1 row of cells, smooth or finely roughened. Calyptra oblong-conic to short-conic, smooth, naked or rarely sparsely hairy, hairs not papillose. Spores 12-14 µm.
Tree trunks, branches in coniferous forests, boulders in shaded habitats; low to moderate elevations; B.C.; Alaska, Calif., Idaho, Oreg., Wash.; Europe.
Orthotrichum consimile is distinguished from superficially similar species of Ulota by its glabrous calyptrae, immersed stomata, and undifferentiated basal laminal cells. From O. pulchellum, it differs by having stomata confined to the proximal portion of the capsule and an exostome of eight yellowish teeth that are finely papillose on the outer surface and finely striate on the inner. Also, O. consimile is much larger and has capsules that are long-exserted and constricted below the mouth when old and dry. The stomata are partially covered by subsidiary cells.