Perennials, 30–150 cm. Stems (commonly branched in distal 1 / 4 ) glabrous or densely spreading-hirtellous, not glaucous. Leaves spreading to ascending; blades 3-or 5-nerved, linear to lanceolate, 37–130 × (2.1–)3–12 mm, lengths 7–20 times widths, abruptly to gradually reduced distally, herbaceous to firm-herbaceous, margins scabro-ciliate, apices obtuse to acuminate, faces usually little and obscurely gland-dotted (26–47 dots per mm²), barely viscid (more so on exposed shores), glabrous or densely spreading-hirtellous. Heads glomerulate, usually in flat-topped arrays (1.5–28 cm diam.), 10–28% of plant heights (branches unequal, giving irregular, broken appearance). Involucres broadly campanulate to campanulate, 3–5.3 mm. Phyllaries often ± yellow basally, outer (at least) usually green-tipped, outer ovate, inner oblong, apices obtuse or broadly acute. Ray florets (7–)17–22(–35). Disc florets (3–)5–7(–13); corollas 2.6–3.4 mm. 2n = 18.
A herb.