new species of Lippia (Verbenaceae) from the Campos eco-region of the Grassland Ecosystems of Río de la Plata, Southeast South America

Abstract

A new species of Lippia (Verbenaceae) from the Campos eco-region of the Grassland Ecosystems of Río de la Plata, Southeast South America. Based on field surveys, studies of nomenclatural types and other specimens and review of literature we found a new species belonging to Lippia sect. Dioicolippia, which is here described as Lippia misionica. It is easily segregated from the others species by its shorter internodes, thicker rhizomes, cushion-like habit, shorter pedicels of pistillate spikes, wider bracts and glandular trichomes covering all the plant. Even with these characteristics, it presents affinity with Lippia coarctata and L. contermina. It dwells in dry environments, mainly on shallow and rocky soils developed on basalts and rhyolites in western and northwestern Rio Grande do Sul state, Brazil, northeast Corrientes and southern Misiones provinces, Argentina, and eastern Alto Paraná department, Paraguay. The new species is detailing illustrated, and data regarding its geographic distribution, phenology, habitat, conservation, and morphological affinities with similar species are given. Furthermore, a key for recognizing of the 22 species currently belonging to Lippia sect. Dioicolippia is provided.