Riccardia is a large genus of thalloid liverworts and notoriously difficult in terms of species recognition. Thirty six species were recognized in the tropical Andes but many of these are not well-defined. In this paper fourteen species are accepted for Colombia and Ecuador; eighteen species and two varieties are reduced to synonymy. Descriptions and illustrations are provided for the accepted species together with a key and data on types, synonymy, geographical distribution, habitat and differentiating characters. Riccardia palmata and R. multifida are excluded from the flora of Colombia and Ecuador. The new combination Riccardia latifrons subsp. parasitans (Steph.) Gradst. & Reeb comb. nov. is proposed and eighteen new lectotypifications are made.
Andes, liverworts, Riccardia, synonymy, taxonomy, tropical America