Mironia is a Neotropical, high elevation genus. Its species have a characteristic reddish color, leaves when wet that are spreading from an erect-sheathing base, long, cylindric capsules, and well-developed, spirally twisted peristome teeth. It is very similar to Bryoerythrophyllum and Rhexophyllum which differ from Mironia in having leaves that are either unistratose at the margins (Bryoerythrophyllum) or irregularly bistratose throughout the lamina (Rhexophyllum). Rhexophyllum also differs from Mironia in having a stem hyalodermis. The distinctions between the three genera, however, are blurred by the presence of bistratose upper leaf cells in some Bryoerythrophyllum species and some collections of M. elongata (first noted by Bartram 1955).

Leptodontium is similar to Mironia in plant size, leaf shape and in having species with dentate upper leaf margins. It differs from Mironia in its usually yellowish green color, unistratose leaf margins, peristome of 16 erect teeth, and the absence of a stem central strand.