Distal leaves long-subulate beyond an ovate, obovate, or elliptic base, 0.9-3.1 mm, leaf base usually strongly differentiated in shape; distal laminal cells short- to long-rectangular. Sexual condition paroicous. Seta 0.5-3 mm. Capsule neck short, obovate. Spores spinose or occasionally spinose-reticulate. Calyptra smooth.
As discussed in detail by A. E. Rushing (1986), Bruchia flexuosa is the most widely distributed and most morphologically variable species of the genus.