Year: 2015

Species of Riccia are found in the tropical and subtropical regions of the world. 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. The vegetative reproduction occurs by means of progressive death and decay of the thallus, by means of tubers and by rhizoids. The sexual reproduction occurs my means of specialized sex organs antheridia and archegonia.