Common Kettlewort

Blasia pusilla is the only species in the liverwort genus Blasia. This species establishes a symbiosis with nitrogen-fixing cyanobacteria of the genus Nostoc, which are housed in special cavities, called auricles, occurring on the ventral (underside) surface of the thallus.

Blasia 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.