Dicranum varium Hedwig, Sp. Musc. Frond., 133. 1801; Anisothecium rubrum Lindberg; A. varium (Hedwig) Mitten; Dicranella howei Renauld & Cardot; D. langloisii Renauld & Cardot; D. rubra Lindberg

Plants 4-15 mm, dirty to light green or yellowish. Leaves erect-spreading or ± falcate-secund, to 2 mm, gradually narrowed from a lanceolate base to a linear-lanceolate, ± keeled limb, blunt or acute at a narrow tip; margins irregularly recurved above the basal portion of the leaf, entire except at the extreme apex; costa percurrent; distal cells oblong-linear, ca. 6-9:1. Sexual condition dioicous. Seta red or pale, reddish yellow, 5-8(-16) mm. Capsule 0.7-1 mm, shortly ovoid, erect or more often inclined to horizontal, curved-asymmetric, smooth, not strumose at base, contracted below the mouth; annulus none; operculum 0.5-0.7 mm, stoutly rostrate; peristome teeth 330-410 µm, divided ¹/3 of its length distally. Spores 14-20 µm, smooth or indistinctly roughened.

Capsules mature spring. Wet, calcareous soil, especially clay, in open, disturbed places, such as roadside ditches; low to high elevations; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Yukon; Ala., Alaska, Ariz., Calif., Colo., Conn., Del., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., S.C., Tenn., Tex., Vt., Va., Wash., W.Va.; Mexico; West Indies (Haiti); Central America (Honduras); Europe; Asia; n Africa; Atlantic Islands (Azores, Madeira, Canary Islands).

The nodding, short, curved-asymmetric, smooth capsules of Dicranella varia have a disproportionately large peristome, and the leaf margins are narrowly recurved proximally or scarcely so. Dicranella howei has been segregated in the past (A. C. Crundwell and E. Nyholm 1977) by its plane leaf margins, costa filling the subula (which is accordingly described as 2-stratose beyond mid leaf), and side walls of exothecial cells no thicker than end walls. Dicranella howei intergrades with the species throughout its range from Iran to Great Britain and on the west coast of North America. Crundwell and Nyholm commented on D. howei and D. varia that there are a small portion of intermediate forms that they have seen from several places in Europe, as well as British Columbia and California. Localities reported above for the United States include literature reports for Alaska (I. A. Worley and Z. Iwatsuki 1970), Alabama (J. C. Wilkes 1965), and Montana (E. Lawton 1971). Keying to Dicranella varia is D. staphylina, reported for the flora area by H. L. K. Whitehouse (2001), which differs in lanceolate distal leaves, medial laminal cells 10-14 µm wide, perichaetial leaves long-acuminate from a sheathing base, and capsules erect.