J. Linn. Soc. Bot. 8: 24. 1864.
Orthotrichum columbicum Mitt., J. Linn. Soc. Bot. 8: 24. 1864. -- Orthotrichum pulchellum var. columbicum (Mitt.) Grout, Moss Fl. N. Am. 2: 130. 1935.
Orthotrichum pulchellum var. longipes Sull. ex Lesq. & James, Man. N. Am. Moss. 175. 1884.
Orthotrichum ulotaeforme Ren. & Card., Bot. Gaz. 15: 42. 1890. -- Orthotrichum pulchellum ssp. ulotaeforme (Ren. & Card.) Kindb., Eur. N. Am. Bryin. 2: 309. 1897.
Orthotrichum hendersonii Ren. & Card., Bot. Gaz. 15: 42. 7A. 1890. nom. nud. in syn.
Orthotrichum pulchellum var. leucodon Vent. in Roell, Bot. Centralbl. 44: 419. 1890.
Orthotrichum pulchellum var. productipes Ren. & Card., Bot. Gaz. 15: 43. 1890.
Plants erect in small green to yellow-green tufts, to 1.5 cm high. Leaves erect spreading when moist but appressed or crispate when dry, lanceolate and broadest near the base, with acute to blunt apices, to 4 mm long, 4–5: 1. Median laminal cells isodiametric with rounded lumens, thick walled with strong corner thickening, to 10 µm wide, with 1–2 low and unbranched papillae on each surface. Basal marginal cells resembling the median cells in both shape and papillosity. Basal juxtacostal cells mostly smooth, short rectangular, 2–4: 1, with thin and straight lateral walls. Margins recurved from base to near the apex, entire or papillose crenate. Costa ending within less than ten cells of apex, lying in a sharply defined abaxial keel. Costa cross-section essentially homogeneous, mostly 3 cells thick, and 6–8 cells wide along the abaxial perimeter. Axillary hairs to 6 cells long but with the laterally inserted ones shorter, to 150 µm, with one basal brown cell, not offset from leaf insertion. Rhizoids mostly near base of plant, smooth, red-brown, to 10 µm in diameter at base, repeatedly branched, Stem cross-section without a central strand, with somewhat pachydermous and hyaline inner corticals and with 1–2 layers of strongly pachydermous, red brown outer cortical cells.
Autoicous with perigonia on the apices of separate short branches. Perichaetia terminal with bracts smaller than vegetative leaves. Capsule exserted on a yellow to yellow brown, smooth and erect seta of 4–5 mm in length. Urn orange-brown, to 2.5 mm long, about 3: 1, erect, strongly sulcate with eight ribs, lightly to strongly strangulate. Operculum conic-apiculate. Annulus well-defined, revoluble. Exothecial cells at capsule mouth very thick-walled and strongly reddened, to 20 µm long, isodiametric to transversely elongate with rounded lumens in up to 4 rows. Exothecial cells at middle of urn quadrate to rectangular, 1–1.5: 1, to 30 µm broad, very thick walled on ridges of capsule with lumen: wall ratio 0.25–1: 1, thinner walled in valleys of the sulcate capsule. Stomata mostly on proximal 1/3 of urn, cryptoporous, only partially obscured by subsidiary cells. Exostome teeth tardily reflexed when dry and old, initially fused in pairs but later separating, pale to almost white, to 300 µm long, finely and densely papillose on dorsal surface but vertically striate on ventral surface. Endostome segments mostly 8, sometimes 16, as long as exostome, smooth to very lightly papillose, arising from only one row of cells. Calyptra 16-plicate, campanulate,about 2: 1, mostly without hairs, sparingly prorate on ridges. Spores to 16 µm, rather coarsely papillose.