of calcareous rocks, light green to black. Alar cells
not differentiated to colored and enlarged. Sexual condition
smooth; annulus ill-formed; peristome teeth smooth. Calyptra
is characterized as tiny acrocarpous plants, with more or less ovate, smooth capsules and linear-lanceolate leaves, and a calcareous substrate as habitat. Seligeria trifaria
(Bridel) Lindberg is excluded.