Paspalum L. (Poaceae) has high species richness and economic importance in the Brazilian flora. Given the importance of regional studies to increase taxonomic knowledge of the species and update the flora of Brazil's list, this study aims to describe the genus and species of Paspalum from Rio Grande do Norte, as part of a larger Flora of Rio Grande do Norte project. Collections were made in all the phytogeographic regions of Rio Grande do Norte during the last four years, and a survey was done of the herbaria with representative collections of local flora. The conservation status of the species was evaluated according to IUCN regional categories. We recorded 16 species of Paspalum in Rio Grande do Norte. Paspalum carinatum Humb. & Bonpl. ex Flüggé, P. gardnerianum Nees and P. pumilum Nees are considered vulnerable in Rio Grande do Norte state, due to man-made pressures on the environment where they occur. However, they are not threatened when evaluated on a global scale. Based on an analysis of populations in the field and under cultivation, we propose to synonymize P. pleostachyum Döll under P. ligulare Nees. Contrary to what is found in the literature, the preference for using the name Paspalum crassum Chase over P. tumidum Kuhlm. is justified. This work includes a key for species identification, morphological descriptions, taxonomic and nomenclatural comments, information on distribution and regional-threat criteria, as well as ecological aspects and illustrations of the species.
grasses; conservation; Northeast region of Brazil; Panicoideae; taxonomy
