Abstract
The genus Surirella comprises around 1700 species, many of them distributed in tropical regions of different continents. As part of a study about geographic distribution of epilithic diatoms from Colombia, we compared samples collected at lotic systems of the Andes, Caribbean, Orinoquia and Pacific biogeographic regions. Samples were analyzed under light and scanning electron microscopy. Although the genus Surirella was poorly represented in the study area, in the River Congo Basin (at an elevation between 724 and 939 m a.s.l.), which belongs the Caribbean Region, we collected samples containing a new species of the group Robustae. Surirella tayronarum spec. nov. has panduriform, isopolar valves with well-developed wings. Among other fine morphological characters, the species has long ribbon-like tendrils at the base of the fenestral bars.