A synopsis of Leucheria Lag. (Asteraceae, Nassauvieae) is presented that adds morphological information about the species and encompasses the taxonomic novelties of the genus (new combinations, new varieties, and new species) established after the last revisionary work in 1976. Because previous work showed that the position of the phyllaries of the involucre, interpreted as paleae, and the life cycle are not good taxonomic characters, a new approach is proposed here for the species distinction. The morphological analysis shows that all but one species (L. floribunda) have plumose pappi with cilia of different lengths, and the surface of the fruits is tuberculate in all species. The type and amount of fruit pubescence are useful in the distinction of some species. As a result of the analysis, the number of species of Leucheria was reduced from 49 to 29. Twenty-seven new lectotypifications (Chabraea barrasiana J. Rémy, Chabraea gayana J. Rémy, Chabraea multifida DC., Chabraea salina J. Rémy, Chabraea salinasi Phil. var. bipinnatifida Phil., Chabraea suaveolens (d’Urv.) DC. var. integrifolia Sch. Bip., Chabraea suaveolens (d’Urv.) DC. var. pinnatifida Sch. Bip., Chabraea viscida Bertero ex Colla, Lasiorrhiza lithospermifolia Poepp. ex Less., Leuceria conyzoides D. Don, Leuceria echioides D. Don, Leuceria fuegina Phil., Leuceria garciana J. Rémy, Leuceria gracilis Albov, Leuceria hieracioides D. Don, Leuceria ibari Phil. var. glandulosa Speg., Leuceria ibari Phil. var. sessiliflora Speg., Leuceria lanata Albov fo. virescens Albov, Leuceria lanata Albov, Leucheria candidissima D. Don, Leucheria coerulescens J. Rémy, Leucheria congesta D. Don, Leucheria floribunda DC., Leucheria rosea Poepp. ex Less., Leucheria runcinata D. Don, Leucheria scrobiculata D. Don, Perdicium suaveolens d’Urv.), five neotypes (Leuceria acanthoides D. Don, Leuceria cinerea D. Don, Leuceria laciniata Hook. & Arn., Leucheria ibari Phil. var. glabrata Speg., Leucheria millefolium Dusén & Skottsb.), seven epitypes (Leuceria divaricata D. Don, Leuceria hoffmannii Dusén, Leuceria lanigera O. Hoffm. ex Dusén, Leuceria meyeniana Walp., Leuceria pulchella D. Don, Leucheria glandulosa D. Don, Trixis senecioides Hook.), 36 new synonyms, and some changes in the species distributions are proposed. A key to the species of Leucheria, brief species descriptions, detailed illustrations, and distribution maps for each species are presented.Fil: Katinas, Liliana. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Apodaca, María José. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Crisci, Jorge Victor. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin
