Chart Riccia Thallus
Riccia fluitans is an aquatic species. The thallus of Riccia is flat , prostrate, dark green coloured and dichotomously branched. On the ventral surface of the thallus are found rhizoids and scales. Rhizoids are of two types. (a) Smooth walled rhizoids and (b) tuberculate rhizoids. The scales are pink in colour due to the presence of Anthocyanin pigment. The internal structure of the thallus is differentiated into photosynthetic region and storage region.