Herb 0.5–1 m high; stems simple or branched, the branches winged; wings entire or denticulate, glabrous or pubescent. Leaves narrowly elliptic or obovate, 2–10 cm long, 0.8–3.2 cm wide, but lower stem leaves may grow to 15 cm long and 5 cm wide, base decurrent into the wings, margins subentire or denticulate, apex rounded to subacute, pubescent to almost glabrous, glandular and slightly aromatic. Glomerule greenish white, ellipsoid to globose, 7–13 mm long, 7–13 mm across, occasionally double, the individual capitula distinct; capitulum stalk 5–30 mm long; receptacle globose to ellipsoid; glomerule bracts linear to lanceolate and 2.5–4 mm long, 0.3 mm wide, acute to acuminate, glandular-puberulous, the lowermost bracts hidden at anthesis; capitula borne on a short secondary receptacle, with 6–15 bracts, these oblanceolate, 1.5–3 mm long, apiculate to rounded, sparsely glandular. Florets: outer florets 15–40, tube ovoid to broadly cylindrical and corky, abruptly narrowed into a filiform tube, 0.7–0.9 mm long, glabrous, minutely toothed distally, style 0.8–1 mm long; inner florets 1–3, tube inflated and corky but abruptly constricted below the lobes and there sparsely glandular, 0.7–1 mm long, lobes 0.3–0.5 mm long, sparsely glandular, anthers 0.6–0.8 mm long, style 1.7–2.8 mm long, briefly bifid. Achenes cylindrical, 0.4–0.6 mm long, puberulous and glandular, briefly stalked on a white glabrous stipe.
