Weisiopsis has broad, rounded to obtuse leaves that are tubulose-incurved when dry and at times have incurved margins when wet. Its upper leaf cells are mostly mammillose-bulging on the ventral surface but plane and smooth on the dorsal surface (one of our species has them bulging on both surfaces); the basal cells are smooth and abruptly enlarged. The costa in Weisiopsis has a single (dorsal) stereid band and enlarged ventral surface cells. The genus is autoicous, has cylindrical capsules and usually distantly spaced peristome teeth (one of our species is eperistomate) that are deeply inserted within the mouth. Zander (1993) placed Weisiopsis in the subfamily Pottioideae tribe Hyophileae and considered it closely related to Ganguleea and Luisierella. Ganguleea, known from Nepal, India, and southeastern Brazil, differs from Weisiopsis in its pleurocarpous condition, consistently eperistomate capsules, and the lack of a stem central strand. Luisierella differs from Weisiopsis in having inflated, thin-walled cells extending up the basal margins in a strong v-shaped pattern.