The genus Chaptalia is represented by ca. 70 species, from northern United States to the center of Argentina; in Brazil there are 17 species. Among the recognizable features of the genus are trimorphic florets, herbaceous habit and florets without staminodes. The present work aimed to survey the native species of Chaptalia in the state of Rio Grande do Sul. The occurrence of 10 species in the State is confirmed: C. arechavaletae, C. cordifolia, C. exscapa, C. graminifolia, C. ignota, C. integerrima, C. mandonii, C. nutans, C. piloselloides e C. runcinata. Chaptalia sinuata is placed by first time as a synonym of C. integerrima. The study presents species descriptions, an identification key, illustrations, conservation data and general information.
Compositae; conservation; Atlantic Forest; Pampa