Baccharis comprises c. 340 species occurring in the Americas. The tufted indumentum, with trichomes having a single adjoining basal cell, and florets functionally unisexual are diagnostic characters of the genus. The Rio de Janeiro state flora contains 55 species of this genus. This work presents the results of taxonomic studies of Baccharis subgen. Molina (Pers.) Heering in Rio de Janeiro state. The subgenus is represented by 18 species belonging to four sections - Caulopterae (8 spp.), Molinae (4 spp.), Baccharidastrum (3 spp.), and Trinervatae (3 spp.). A key for the identification of sections and species, plus morphological descriptions, illustrations, and comments on geographic distribution and ecology are provided. Three species are new records and five are excluded from the state checklist of species.
Astereae; Compositae; High Altitude Grasslands; Atlantic Rain Forest; Coastal Vegetation
