Taxonomic Revision of the Neotropical Genus Werneria (Compositae, Senecioneae)

<i>Werneria </i>is a neotropical genus belonging to the tribe Senecioneae (Compositae) that is mainly distributed through the highlands of the Andes. Only a single species, <i>W. nubigena</i>, has a trans-Andean distribution and reaches the Tacaná Volcano in southern Chiapas (Mexico). The traditional concept of <i>Werneria </i>was significantly narrowed at the end of the twentieth century after segregating several species and accommodating these mostly in the genus <i>Xenophyllum</i>. As currently circumscribed, it includes rosettiform or scapiform species characterized by usually displaying involucral bracts that are fused at the base, supplementary bracts commonly absent, usually radiate but sometimes discoid or disciform capitula, white or yellow ray corollas (when present), a balusterform filament collar, and style branches that are truncate and have a crown of sweeping hairs. The first modern, comprehensive revision of this genus recognizing 27 species is presented here. <i>Werneria heteroloba </i>and <i>W. obtusiloba </i>are synonymized with <i>W. pinnatifida</i>, and <i>W. acerosifolia </i>is synonymized with <i>W. staticifolia</i>. Moreover, five infraspecific names and three supraspecific names are synonymized. Detailed descriptions, distribution maps, photographs of living plants (except for <i>W. cochlearis</i>), and a list of all specimens examined are provided for each accepted species. An identification key to the species and a list of exsiccatae are also given. Eight species are illustrated, two of them for the first time. The following names are lectotypified: <i>Werneria brachypappa </i>Sch. Bip., <i>W. caespitosa </i>Wedd., <i>W. calyculata </i>Turcz., <i>W. canaliculata </i>Sch. Bip., <i>W. carnulosa </i>A. Gray, <i>W. densa </i>Benth., <i>W. disticha </i>Kunth, <i>W. glaberrima </i>Phil., <i>W. glandulosa </i>Wedd., <i>W. heteroloba </i>f. <i>microcephala </i>Rockh., <i>W. mandoniana </i>Wedd. ex Klatt, <i>W. nubigena </i>Kunth, <i>W. nubigena </i>var. <i>caulescens </i>Wedd., <i>W. nubigena </i>var. <i>dombeyana </i>Wedd., <i>W. orbignyana </i>Wedd., <i>W. orbignyana </i>var. <i>breviradiata </i>A. Gray, <i>W. orbignyana </i>var. <i>longifolia </i>Rockh., <i>W. pectinata </i>Lingelsh., <i>W. plantaginifolia </i>Wedd. ex Klatt, <i>W. pygmaea </i>var. <i>caespitosa </i>Wedd., <i>W. rhizoma </i>J. Rémy, <i>W. solivifolia </i>Sch. Bip., <i>W. staticifolia </i>Sch. Bip., <i>W. staticifolia </i>var. <i>celmisioides </i>Wedd., and <i>W. villosa </i>A. Gray. The names <i>Werneria knocheae </i>Perkins, <i>W. minima </i>Walp., <i>W. minima </i>var. <i>pygmaea </i>Walp., and <i>W. stuebelii </i>Hieron. are neotypified, and an epitype is designated for <i>W. glandulosa</i>. At the supraspecific level, the name <i>Werneria </i>sect. <i>Integrifoliae </i>Rockh. is typified.