Rev. Bryol.21: 33. 1894 ,
Northern Pacific Radiant distribution, nw North America, e Asia (Japan, e Siberia).
Diagnostic features of Bartramiopsis include the serrate lamellae, the ciliate sheath, the terete capsule, which is flared at the mouth and tapers toward the base, the absence of a peristome, and the naked calyptra. The genus occupies an isolated position in the family, and the gametophyte has a curious un-polytrichoid appearance. The bistratose lamina and the absence of even a rudimentary peristome have led to its association with Lyellia, but the capsule in that genus is strongly dorsiventral with 2 sharp angles, with a bowl-shaped disc at the capsule mouth and the blunted columella apex forming a “stopper” in the small central opening. In Bartramiopsis, the exserted columella is broadly flared, extends to the capsule rim, and persists long after the operculum is shed.