Abstract
Paepalanthus and Syngonanthus are the largest genera of the Neotropical Eriocaulaceae, and both present many taxonomic and nomenclatural problems. Based on field observations and detailed analysis of type collections, we suggest nomenclatural and taxonomic changes to solve the problems regarding six species occurring in Rio de Janeiro and Santa Catarina. We propose species status (i.e., P. kleinii) for Paepalanthus leiseringii var. kleinii and five taxa are newly synonymized: P. bradei (=P. macaheensis), P. gounelleanus (=P. pseudotortilis), P. tortilis var. glaberrimus (= P. tortilis), S. caulescens var. angustifolius (=S. caulescens), and S. caulescens var. proliferus (=S. caulescens). We provide comments on morphology and citation of type collections for all taxa. For Paepalanthus leiseringii var. kleinii we also provide illustrations and a protologue.