Contr. U.S. Natl. Herb. 4: 134, plate 10. 1893.
Annuals, 1–25 cm. Stems erect to spreading, simple or ± branched (very slender). Leaves cauline; opposite (proximal) or alternate; obscurely petiolate or sessile; blades linear to narrowly oblong-oblanceolate, margins entire, faces tomentose to glabrate, gland-dotted. Heads discoid, borne singly or (2–5) in clusters (at stem tips). Involucres cylindric or narrowly turbinate, 3–4(–6) mm diam. Phyllaries persistent, 4–7 in ± 1 series (distinct, oblong, unequal, glandular-puberulent). Receptacles ± flat, ± knobby, epaleate. Ray florets 0. Disc florets 4–9; corollas yellow, lobes 5, short-triangular (anther bases short-sagittate, appendages short-triangular; style branches linear, tapering). Cypselae terete, linear-clavate, narrowly ribbed, minutely glandular-puberulent, glabrescent; pappi falling (in rings), of 11–17 (basally connate) oblanceolate, fringed, obtuse scales. x = 9.