Taxonomic revision of the peculiar genus Xylopodia (Loasaceae) with a new species from Argentina and Bolivia demonstrating an atypical trans-Andean disjunction

Loasaceae subfam. Loasoideae are a nearly exclusively American plant group with a center of diversity in Peru. Numerous new taxa have been described over the past decades; one of the most striking discoveries was that of the narrowly endemic Xylopodia with the single species Xylopodia klaprothioides in Peru, Dpto. Cajamarca in 1997. Surprisingly, field studies in the past years have resulted in the discovery of material clearly belonging to the same genus in both Bolivia and northern Argentina, approximately 1500 km SE of the next known population of Xylopodia in Contumazi, Peru. A closer examination shows that Argentinian and Bolivian material belongs to a single species, clearly different from Xylopodia klaprothioides. We here describe Xylopodia laurensis and the entire genus is revised. Both species are illustrated, all aspects of their biology and ecology are portrayed and their threat status is discussed.