Taxonomic Revision of Trichogonia (Eupatorieae, Asteraceae): A South American Genus

Abstract Eupatorieae is one of 43 tribes circumscribed in Asteraceae and it is characterized mainly by opposite leaves, discoid heads, tubular, white, pink, or lilac florets, style branches linear to clavate, and cypsela walls with black or carbonized resin-like deposits in mature stages. The tribe is essentially Neotropical, found in Mexico, Central America, and South America, with 29 genera, of which Trichogonia is one of them. Trichogonia is found only in South America and is characterized by stems with prominent longitudinal ridges and the presence of dense pubescence on the upper throat and lobes of the corolla. The present work is a taxonomic revision of Trichogonia with illustrations and geographic distribution maps for every species. Morphological data were obtained from the field and from specimens from 26 herbaria. From a total of 20 recognized species, 17 occur in Brazil, one is endemic to Bolivia (T. capitata), and two are endemic to Paraguay (T. chodatii and T. phlebodes). From the species cu...