Abstract
Seven species of Siphula Nylander have been found in Venezuela (including Páramos and Guayana Highlands). Three species from the Guayana Highlands viz. S. chimantensis V. Marcano, S. subsimplex V. Marcano and S. subpteruloides V. Marcano are described as new to science. A key to the species is presented together with data on morphology, chemistry, variation, taxonomy, habitat and distribution. The data indicate that of the taxa reported from Venezuela, four are known only from the Guayana Highlands, one is known only from the neotropics, and two are pantropical. The high concentration of Siphula species seen in the Guayana Highlands suggests that this region constitutes an important centre for speciation and endemism for the genus.