Heads radiate, the rays yellow, pistillate and fertile, persistent and becoming papery; invol bracts herbaceous at least distally, in 1–3 subequal series, or the outer ones enlarged and leafy; receptacle convex to conic, chaffy throughout, its bracts concave and clasping, subtending the rays as well as the disk-fls; disk-fls perfect and fertile; style-branches flattened, with a short, hairy appendage; achenes nearly equably quadrangular (or those of the rays triquetrous); pappus none, or a short irregular crown or a few teeth; herbs with opposite, petiolate lvs. (Kallias) 13, New World.
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