Fruct. Sem. Pl. 2: 355, plate 157, fig. 3. 1791.
Annuals, (5–)10–30+ cm; taprooted. Stems 1–10+ (scapiform), erect, simple or branched distally, glabrous. Leaves mostly basal; obscurely petiolate; blades oblanceolate to spatulate, margins dentate (faces usually scabridulous, mostly near margins). Heads borne singly or (2–3) in loose, corymbiform arrays. Peduncles inflated (fistulose) distally, not bracteate. Calyculi 0 or of 1–10+, lanceolate bractlets. Involucres broadly campanulate or urceolate, 4–8 mm diam. Phyllaries 10–22+ in 1(–2) series (basally connate), lanceolate to lance-linear (abaxially keeled proximally), equal or subequal, margins little, if at all, scarious, apices acuminate. Receptacles flat, pitted, glabrous, epaleate. Florets 20–50+; corollas yellow. Cypselae dark brown, obovoid, not beaked, ribs 8–10 (3–5 stronger), stramineous, faces smooth or rugose between ribs, glabrous; pappi 0. x = 9.