Dana Griffin, III
Plants small to robust, in loose to dense tufts or sods, mostly tomentose below. Stems erect or occasionally decumbent, 0.5--15 cm, simple, fastigiate or with a subfloral whorl of branches. Leaves erect-appressed to spreading-recurved, ovate-lanceolate to lance-subulate or linear, acute, acuminate or rarely obtuse, sometimes abruptly enlarged and clasping at base, unbordered or weakly bordered, toothed distally or throughout, teeth single or paired; laminal cells rounded quadrate to oblong, rectangular or linear, mostly firm-walled, prorulose or mammillose at one or both ends, rarely centrally papillose or smooth, usually enlarged, lax, smooth and hyaline toward base, not to weakly differentiated at basal angles (or with distinct alar regions). Sexual condition dioicous, autoicous or synoicous; perigonia gemmiform or discoid, paraphyses filiform or clavate; perichaetial leaves often longer and with a laxer areolation, otherwise little different from stem leaves. Seta terminal, often appearing lateral by innovations, mostly single, rarely clustered, mostly elongate. Capsule inclined or horizontal, rarely pendulous or erect, subglobose or ovoid, usually asymmetrical and oblique mouthed, typically furrowed, rarely smooth or irregularly wrinkled when dry; annulus usually none; operculum convex or umbonate, beak short, blunt or rarely rostrate; peristome double, single, rudimentary or lacking, inserted well below the mouth, the 16 teeth lanceolate, yellow-brown to reddish-brown, smooth or papillose, usually unbordered, usually with prominent trabeculae and often with intermediate thickenings in upper half; endostome, when present, usually well developed, occasionally adhering in fragments to exostome or shorter and keeled, sometimes absent, segments gaping and split along the median line, cilia 1--3, usually short, sometimes lacking, never appendiculate, basal membrane typically high. Calyptra cucullate, naked, smooth. Spores spherical to reniform, papillose.
Genera 9--10, species 419 (5 genera, 22 species in the flora); worldwide, primarily montane tropical.
The more or less globose (apple shaped), typically furrowed capsules and the narrow leaves with prorulose cells are distinctive family characters. The roughenings are mostly eccentric over the lumen. Infrequently, most of the laminal cells are smooth (a condition often associated with submergence in boggy habitats) or, as in Plagiopus, the leaves develop a striated cuticle which can appear papillose in section.
Crum, H.A. and L.E. Anderson. 1981. Bartramiaceae. In: Mosses of Eastern North America. Vol. 1, pp. 634--656. New York. Flowers, S. 1935. Bartramiaceae. In: A.J. Grout, Moss Fl. No. Amer. Vol.II, part 3, pp. 152--180. Newfane, Vermont. Flowers, S. 1973. Mosses: Utah and the West. Provo, Utah. Griffin, D.,III and W.R. Buck 1989. Taxonomic and phylogenetic studies on the Bartramiaceae. Bryologist 92: 368--380.