Ricciocarpos natans, is the only species of the genus Ricciocarpos, the sister genus to all other species in the family Ricciaceae. R. natans is a liverwort, one of the three ancient lineages within the non-vascular plant group, the bryophytes. As bryophytes do not have vascular tissue to facilitate water conduction, their tissues are at a higher risk of drying out and thus must maintain alternative strategies to resist desiccation. Due to their simple structure and desiccation tolerance, bryophytes are useful for studies pertaining to abiotic stress in the environment, especially for studies of water-related stress. Furthermore, studies of bryophytes can be used to gain insights into the evolution of land plants and decipher strategies related to adaptation to terrestrial environments. R. natans is distinct due to its ability to exhibit both a land and aquatic form, and therefore can be studied to understand responses to changes in water stress. The molecular distinction and differential gene expression pattern between terrestrial and aquatic forms of R. natans will provide an insight into the mechanisms and pathways relating to terrestrial adaptation. Further, R. natans is monoecious, but is derived from a dioecious ancestor whose sex was determined by dimorphic sex chromosomes, providing a model to examine the genomic response to the loss of a sex chromosome.