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

Werneria is a neotropical genus belonging to the tribe Senecioneae (Compositae) that is mainly distributed through the highlands of the Andes. Only a single species, W. nubigena, has a trans-Andean distribution and reaches the Tacaná Volcano in southern Chiapas (Mexico). The traditional concept of Werneria was significantly narrowed at the end of the twentieth century after segregating several species and accommodating these mostly in the genus Xenophyllum. 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. Werneria heteroloba and W. obtusiloba are synonymized with W. pinnatifida, and W. acerosifolia is synonymized with W. staticifolia. Moreover, five infraspecific names and three supraspecific names are synonymized. Detailed descriptions, distribution maps, photographs of living plants (except for W. cochlearis), 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: Werneria brachypappa Sch. Bip., W. caespitosa Wedd., W. calyculata Turcz., W. canaliculata Sch. Bip., W. carnulosa A. Gray, W. densa Benth., W. disticha Kunth, W. glaberrima Phil., W. glandulosa Wedd., W. heteroloba f. microcephala Rockh., W. mandoniana Wedd. ex Klatt, W. nubigena Kunth, W. nubigena var. caulescens Wedd., W. nubigena var. dombeyana Wedd., W. orbignyana Wedd., W. orbignyana var. breviradiata A. Gray, W. orbignyana var. longifolia Rockh., W. pectinata Lingelsh., W. plantaginifolia Wedd. ex Klatt, W. pygmaea var. caespitosa Wedd., W. rhizoma J. Rémy, W. solivifolia Sch. Bip., W. staticifolia Sch. Bip., W. staticifolia var. celmisioides Wedd., and W. villosa A. Gray. The names Werneria knocheae Perkins, W. minima Walp., W. minima var. pygmaea Walp., and W. stuebelii Hieron. are neotypified, and an epitype is designated for W. glandulosa. At the supraspecific level, the name Werneria sect. Integrifoliae Rockh. is typified.