Orthotrichum spjutii Norris &Vitt, Nova Hedwigia. 56(2): 259. 1993.
Plants to 3.5 cm. Stem leaves erect-spreading to spreading when moist, loosely erect-appressed to erect-curved when dry, 2--4 mm, broadly lanceolate, ovate-lanceolate, or ovate-ligulate, bluntly acute to obtuse; margins strongly revolute from just below apex to near base, papillose-crenulate; distal laminal cells 10--15 µm wide, 1-stratose, irregularly rounded to isodiametric, with obvious corner thickenings, strongly papillose, papillae forked and densely arranged; basal laminal cells long-rectangular to elongate, pellucid, smooth, lateral walls somewhat irregularly thickened, shorter, narrower, somewhat papillose along the margins. Sexual condition goniautoicous. Seta 1--1.5 mm. Capsule emergent, often rather shortly so; urn oblong to shortly-cylindric, erect, nearly smooth to lightly 8-ribbed sometimes becoming deeply 8-ribbed and constricted with flaring mouth when old and dry; stomates superficial; peristome superficially absent, of more or less 16, very short, blunt, papillose teeth 1-3 cells high. Calyptra ovoid-campanulate, mitrate, plicate, hairy; hairs with spiculose papillae throughout. Spores 8--11 µm, finely papillose.
Shaded forests near stream beds, canyons, usually in mountainous areas, deciduous trees, rarely on shaded rocks; 2600 m; Calif. Endemic.
Orthotrichum spjutii, a species confined to California, is best recognized by the following combination of characters: large multifid distal leaf cell papillae; strongly revolute leaf margins; emergent, oblong capsules; peristome reduced to 1--2 cells and seemingly absent; and small spores.