Perennials (or annuals), 50–120 cm (usually glabrous, sometimes sparsely pubescent distally on peduncles). Stems erect. Leaves sessile; blades usually linear or lanceolate, rarely subelliptic, 50–140 × 4–17 mm, bases ± connate, margins entire, minutely serrate, or spinulose-serrate. Heads 20–100+, in dense, scorpioid-cymiform arrays. Calyculi of 1–3 linear-lanceolate bractlets 4–6 mm (often surpassing involucres). Involucres suburceolate, oblong-angular, 3.6–4.5 mm. Phyllaries 5–6(–9), oblong or ovate-orbiculate. Ray florets 0 or 1; laminae yellow, ovate-spatulate, 2–2.8 × 1.5–2 mm. Disc florets 9–14; corolla tubes 0.8–1 mm, throats funnelform, 1.3–1.5 mm. Cypselae oblong-oblanceolate or linear, 1.2–1.8 mm; pappi 0. 2n = 36.
Home