Judith A. Harpel
Plants minute and bud-like or merely small, forming dense turfs or scattered patches; protonema producing chlorophyllose, perpendicular protonematal flaps, which are persistent or disappear after the development of the gametophores. Stems erect, to 1 cm. Leaves ovate or lanceolate, erect, three-ranked and appressed or spreading, costate or ecostate, cells smooth, rounded-hexagonal or oblong-rhomboid, basal cells elongate; Sexual condition autoicous; archegonia and antheridia on short stems at the plant base. Seta straight or flexuose, smooth or papillose. Capsule exserted, single, cylindric, ovate or shortly oblong-cylindric; peristome of four, single, unsegmented, narrowly triangular, multicellular teeth; annulus lacking. Calyptra mitrate, smooth or plicate, naked. Spores green to yellowish, 10--16 µm, spheric, smooth or finely papillose.
Genera 2, species 4, varieties 2 (2 genera, 4 species, 2 varieties in the flora): circumboreal, disjunct to the Southern Hemisphere.
Crum, H. A. and L. E. Anderson. 1981. Mosses of Eastern North America. 2 vols. New York. Ireland, R. 1982. Moss Flora of the Maritime Provinces. National Museums of Canada. Publications in Botany 13. Ottawa, Canada. Nyholm, E. 1969. Illustrated Moss Flora of Fennoscandia. II. Musci Fasc. 6. Swedish Natural Science Research Council. Stockholm. Pp. 651--655. Murray, B. M. 1987. Illustrated Moss Flora of Arctic North America and Greenland. 3. Andreaeaobryaceae--Tetraphidaceae.