Abstract The monophyly of Flourensia was examined for the first time by sequencing the nuclear ITS and plastid psbA- trnH regions in 18 species of the genus, analyzing them along with representatives of the remaining genera of subtribe Enceliinae. Results showed strong evidence for the polyphyly of Flourensia identifying two well-supported groups: Flourensia, a clade from North America including the type F. laurifolia, and another clade, here designed as the new genus Austroflourensia, containing the South American species. Austroflourensia is related to the other four genera composing the subtribe Enceliinae, whereas Flourensia s.s. is sister to all of them. Austroflourensia can be mainly distinguished by having a shrubby or subshrubby habit, capitula always radiate usually arranged in weakly cymose-corymbose capitulescences, phyllaries 2-3-seriate, and disc corollas shortly dentate. This paper proposes twelve new combinations to accommodate species previously described in the genus Flourensia and provides emended descriptions of Flourensia and the new genus Austroflourensia. The illustration of the type of the new genus, a distribution map, and a key to the genera of Enceliinae are also provided.

A critical analysis of the novel entities described by Lorentz and Niederlein in the "Scientific Report of the Desert Expedition in 1879", is presented. The year of publication of this Report (1883 and not 1881) is clarified. The taxonomical status for each taxon is established and data of the respective labels and protologues are given. The current accepted name for each binome is added and some lectotypifications are proposed.

Se presenta un análisis crítico de las entidades novedosas descriptas por Lorentz y Niederlein en el Informe Científico correspondiente a la Expedición al Desierto, en 1879. Se pone en claro que la fecha de publicación del citado Informe es 1883 y no 1881. Se establece el estatus taxonómico para cada taxón y se brindan datos de las respectivas etiquetas y protólogos. Se agregan los nombres actuales de cada binomio y se proponen algunas lectotipificaciones.