Dicranella schreberiana
Mosses E. N. Amer. 1: 169. 1981,.
Plants 5–20 mm (or rarely more), yellowish. Leaves to 3 mm, abruptly narrowed from an oblong to obovate, sheathing base to a flexuose-spreading or squarrose limb, blunt or acute at a slender apex, entire or ± toothed above or only at the apex; costa percurrent or shortly excurrent, often somewhat toothed abaxially above; cells rectangular, 7–15 µm wide, 2–3: 1. Sexual condition dioicous (also reportedly autoicous). Seta red, 7–12 (–25) mm. Capsule nodding, curved-asymmetric, usually somewhat strumose at base, smooth or faintly or rarely distinctly striate, 0.8–1 mm; annulus none; operculum curved-rostrate; peristome teeth 360–450 µm, forked less than 1/2 distally. Spores 13–18 µm, smooth or nearly so.
Phenology: Capsules mature fall.
Habitat: Wet soil of banks, especially roadside ditches, or in crevices of cliffs
Elevation: medium to high elevations
Distribution
Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., N.S., Ont., Que., Yukon, Alaska, Calif., Colo., Idaho, Maine, Mass., Mich., Mont., N.J., N.Y., Ohio, Oreg., Pa., S.Dak., Utah, Wash., Wis., Wyo., n, c Europe, e Asia (Japan), Pacific Islands (New Zealand), Australia
Discussion
Dicranella grevilleana is scarcely distinct from D. schreberiana. In its best expression, its leaves are mostly entire, with cells only about 6 µm wide, and capsules faintly or rarely distinctly striate when dry and empty. Dicranella schreberiana, in a narrow sense, has leaves usually denticulate above, with broader cells, 8–14 µm wide, and smooth capsules. The differences, small and scarcely constant, can perhaps be related to relative environmental wetness. Dicranella schreberiana var. robusta also seems no more than an ecotype of particularly wet habitats. It is larger and has serrated leaf margins and particularly broad leaf cells. A large expression of the species greatly resembles D. palustris, which has leaves entire except for crenulations at the extreme apex. Literature reports among the states cited were: New Jersey and Oregon (E. Lawton 1971), Massachusetts (F. J. Hilferty 1960), and Utah (S. Flowers 1973).
Selected References
None.