Small Limestone Moss

Seligeria calcarea (Dicks.) B.S.G. Bryol. Eur
(33-36:) Selig. 4. 1846.
Bryum catcareum Dicks. PI. Crypt. Brit. 2: 3. 1790. Weisia calcarea Hedw. Sp. Muse. 66. 1801.
Plants small, gregarious; stems short, less than 1 mm. high, leafless below, branching by basal buds: leaves crowded at the apex, erect, short, less than 1 mm. long, ovate, abruptly subulate from a broad clear, clasping, sometimes toothed base; costa broadening into and forming the blunt, thick, subulate awn; basal cells clear, rectangular, the upper ones dense, square; perichaetial leaves erect, clasping, longer and broader, 0.5-1 mm. long. Autoicous: antheridia in basal buds, the bracts veinless: seta 2 mm. long, thick, erect, twisted: calyptra cucullate, 0.75 mm. long: capsule ovoid-pyriform, 0.5 mm. long; neck distinct; walls thickened, the cells irregular; stomata absent or imperfect and median; mouth broad, bordered by 3-4 rows of cells; lid conic-rostrate; peristome incurved or recurved, red-brown; teeth fragile, smooth, and thickened at the joints: spores 14-18 ^i in diameter, slightly rough, maturing in summer.
Type locality: Newmarket Heath, England.
Distribution: Very rare, on wet limestone rocks, near Columbus, Ohio; Ontario to Manitoba; also in Europe.