Blasia pusilla is the only species in the liverwort genus Blasia. It is distinguished from Cavicularia by the presence of a collar around the base of the sporophyte capsule, and a scattered arrangement of sperm-producing antheridia. Rhizoids and gemmae of Blasia may be parasitized by the mushroom Blasiphalia. The genus name of Blasia is in honour of Blasius Biagi (ca. 1670 - 1735), an Italian clergyman from village of Vallombrosa.