6. Ulota hutchinsiae (Smith) Hammar, Monogr. Orthotrich. Ulot. Suec. 27. 1852.
Orthotrichum hutchinsiae Smith in J. E. Smith et al., Engl. Bot. 36: plate 2523. 1813
Plants 0.4-4 cm. Stems erect. Stem leaves erect-appressed, stiff, ± slightly curled or twisted around stem, not contorted or crisped when dry, narrowly lanceolate-oblong to lanceolate, 1.4-2.2 mm; base oblong; margins ± recurved to near apex; apex acute to obtuse; basal laminal cells rectangular to elongate-rectangular; distal cells 7-14 µm, papillae conic or clavate, small or large. Specialized asexual reproduction absent. Sexual condition autoicous; perichaetial leaves not differentiated from stem leaves. Seta 2.5-3.5 mm. Capsule oblong-elliptic to cylindric-fusiform, 1.1-2 mm, slightly to moderately 8-ribbed 1/3-1/2 length, mouth wide but constricted below mouth or evenly tapering to seta from mouth; stomata in neck; peristome double; exostome teeth rarely split to 16, reflexed, densely papillose; endostome segments 8, papillose-striate. Calyptra oblong-conic, very hairy. Spores 9-16 µm.
Varieties 2 (2 in the flora): North America, Europe, Asia.
Ulota hutchinsiae is distributed continuously in eastern North America from Newfoundland and northern Quebec west to western Ontario and south to Georgia and Alabama, and is disjunct in western Arkansas and eastern Oklahoma, the Black Hills of South Dakota, eastern Arizona, and southeastern Alaska. This species is distinguished by its erect, non-crisped leaves, cylindric, fully exserted capsules slightly smaller at the mouth, and poorly differentiated marginal basal cells. Ulota hutchinsiae resembles species of Orthotrichum, especially O. anomalum. However, O. anomalum occurs on calcareous substrates and has capsules with immersed stomata and eight long and eight short capsule ribs. Ulota curvifolia, another rock-growing species, is more northern in distribution and has somewhat twisted and curved leaves.