Annuals, 15–120 cm. Stems fistulose. Leaves: proximal blades entire or serrate, faces glabrous (margins and midribs sometimes scabrous or hispid). Heads in open, corymbiform, racemiform, or paniculiform arrays. Bracts subtending heads usually not overlapping involucres. Phyllaries evenly stipitate-glandular, including margins and apices, usually with some non-glandular, non-pustule-based hairs as well. Paleae in 1 series. Ray florets (8–)10–14; laminae deep yellow, 5–10 mm. Disc florets 28–60, all functionally staminate; anthers yellow or brownish. Pappi 0 (reportedly sometimes rudimentary). 2n = 20.
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