Plants 4--10 mm. Stem leaves erect, not contorted when dry, ovate- to oblong-lanceolate, 2--2.7 mm, acute to ± narrowly obtuse; margins appearing revolute to near apex, entire; distal laminal cells 7--12 µm wide, 1-stratose except at margins where 2- to 3--stratose, with 2--3 conic, sometimes forked papillae; basal laminal cells quadrate to rectangular, non-nodose. Sexual condition goniautoicous. Seta 0.8 mm or less in length; capsules immersed to 1/2 emergent; urn oblong-ovate to oblong, 1.1--1.8 mm, distinctly 8-ribbed; stomates immersed; peristome single; endostome segments none; endostome segments none, exostome teeth 16, incurved-erect to spreading recurved, finely papillose, granulose, or reticulate-papillose. Calyptra oblong-conic, covered with papillose hairs. Spores 13--17 µm.

Found exclusively on dry, exposed, calcareous or dolomitic bluffs and rock faces; moderate elevations; Man., Ont., Que.; Ala., Ark., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Minn., Mo., N.J., N.Y., N. C., Ohio, Okla., Pa., S.C., S.D., Tenn., Vt., Va., W.Va.

Orthotrichum strangulatum is a variable species now including several described taxa as synonyms. The 1-stratose leaves with 2- to 3-stratose margins, blackish plants of dry calcareous rocks, and strangulate, immersed to shortly emergent, strongly 8-ribbed capsules define this species of eastern North America.