Plants small to medium-sized, occasionally large, usually in ± compact turfs. Stems 0.1-3 cm, bearing lateral gametangia when fertile. Leaves erect to ± spreading, narrowly lanceolate to ovate-lanceolate, 0.5-1.3 mm; base not decurrent; margins plane [rarely recurved], finely serrate to serrulate near apex, rarely entire; apex acute or short-acuminate; costa ending well before apex to subpercurrent; distal medial laminal cells hexagonal to rhomboidal; marginal cells undifferentiated. Specialized asexual reproduction absent or rare, by axillary bulbiform gemmae. Sexual condition dioicous or synoicous; perigonia and perichaetia on short lateral branches; perigonial leaf apex short-acute; perichaetial leaves usually smaller than vegetative leaves, lanceolate to narrowly linear-lanceolate. Seta single, color various, straight or bent. Capsule erect or inclined to 30°, narrowly cylindric to pyriform, 1-4 mm, neck shorter than urn; exothecial cells near mouth in 1-3 rows, medial cell walls straight or slightly sinuate; stomata superficial; annulus revoluble; operculum convex, short- to long-conic; peristome single or double, appearing single, usually 4:2:4; exostome, when present, white to hyaline, teeth narrowly acute- or blunt-triangular, sometimes irregular, often reduced or absent, weakly or not trabeculate, papillose; endostome basal membrane rudimentary or scarcely exceeding capsule rim, segments sometimes absent, or narrow, slightly keeled, not perforate, cilia absent.
SELECTED REFERENCES Shaw, A. J. 1994. Systematics of Mielichhoferia (Bryaceae: Musci) II. Morphological variation among disjunct populations of M. elongata and M. mielichhoferiana. Bryologist 97: 47-55. Shaw, A. J. and H. A. Crum. 1984. Peristome homology in Mielichhoferia with a taxonomic account of the North American species. J. Hattori Bot. Lab. 57: 363-381. Shaw, A.J. and P. E. Rooks. 1994. Systematics of Mielichhoferia Nees & Hornsch. (Bryaceae: Musci) I. Morphological and genetic analyses of M. elongata and M. mielichhoferiana. Bryologist 97: 1-12.