Gymnostomum rauanum Austin; Mollia viridula (Withering) Lindberg; Weissia andrewsii E. B. Bartram; W. brandegeei Austin; W. controversa var. australis (Austin) Schornherst; W. controversa var. longiseta (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson; W. controversa var. wolffii (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson; W. curvicaulis Bridel; W. longiseta Lesquereux & James; W. microodonta Hedwig; W. viridula var. nitida Renauld & Cardot; W. wolfii Lesquereux & James

Leaves short- to long-lanceolate, base weakly differentiated to ovate, shoulders weak or absent, distal laminal margins strongly and usually but not always sharply incurved or inrolled, apex plane to channeled, acute, mucro usually weak, of 1-5(-8) cells; costal adaxial stereid band smaller than the abaxial; distal laminal cells 6-13 µm wide. Sexual condition monoicous. Seta elongate, 0.3-0.8 cm. Capsule stegocarpic, long-ovate to cylindric, operculum differentiated, falling, peristome present, teeth rudimentary to lanceolate, or occasionally absent.

Capsules mature throughout year depending on area of the flora. Weedy, soil, rock, disturbed areas, roadsides, fields, acid or calcareous substrates; Greenland; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon; Ala., Alaska, Ariz., Calif., Colo., Fla., Ga., Idaho, Ill., Iowa, Kans., Ky., La., Mass., Mich., Mont., Nev., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Okla., Oreg., Tenn., Tex., Utah, Va., Wash., Wis.; Mexico; West Indies; Central America; South America; Eurasia; Africa; Pacific Islands; Australia.

This treatment of Weissia controversa follows the study of A. Stoneburner (1985), which justifiably included W. andrewsii, and, agreeing with H. A. Crum and L. E. Anderson (1981), pointed out the great variation in peristome development including occurrence of both eperistomate and peristomate capsules in the same collection. The present treatment includes all flora area reports of W. condensa, a morphologically distinct European species with characters as listed in Excluded Species. Rhizoidal gemmae were reported by W. D. Reese (1988) but these are apparently rare. Weissia viridula Bridel is an illegitimate name that has been much used for this taxon.