A NEW SPECIES OF THE SOUTH-AMERICAN GENUS NASSAUVIA (COMPOSITAE, MUTISIEAE) FROM CHILEAN PATAGONIA

Nassauvia coronipappa Arroyo and Marticorena, from Cerro Donoso in eastern Chilean Patagonia, is described and illustrated. It is distinguished by trifid inner involucral bracts and persistent, brief, laciniate-dentate, crown-like pappus incompletely surrounding summit of the achene. The distinctive pappus may be related to selection, in harsh alpine habitats, against dispersal away from nurse sites. Nassauvia coronipappa belongs to subgenus Nassauvia. It is seen as a relict member of an independent line of evolution, whose closest affinities are with section Nassauvia of that subgenus.