Exostigma, a New Genus of Astereae (Compositae) from Southern South America.

The article describes Exostigma, a new genus of Astereae Compositae, that includes Exostigma notobellidiastrum and Exostigma rivulare, South American species transferred from Podocoma, based on corolla, style and cypsela characters. Exostigma notobellidiastrum have broadly obovate to suborbicular proximal leaf blades and ray floret corollas that are five to 5.2 millimeters long while Exostigma rivulare have narrowly elliptic proximal leaf blades and densely hairy ray floret corollas.