The order of the liverworts containing the families Riellaceae, Sphaerocarpaceae.
Sites 2
- Sphaerocarpaceae Description of the characteristics of this family, the genus Sphaerocarpus and the species S. cristatus, donnellii, drewii, hians, sphaerocarpus and texanus.
- Riellaceae Description of the characteristics of this family, the genus Riella and the species R. americana and affini. Riella is unique among hepatics in living submerged in fresh or brackish water in arid and semiarid regions.