Centipeda pleiocephala

Erect slender annual, to 30(–40) cm high; branches glabrous except for a few cottony hairs on young growth and occasionally in axils. Leaves more or less oblong to narrowly obovate, 8–25 mm long, 2–7 mm wide, serrate, surfaces glabrous, resin-dotted. Capitula hemispherical to biconvex at anthesis, 2–4.5 mm diam., 2–4 racemosely arranged (rarely solitary), axillary, lowest capitulum sessile or subsessile, the upper 1–3 with peduncles to c. 5 mm long; involucral bracts spathulate to obovate with ruminate membranous margins, 1–1.5 mm long; receptacle convex; female florets c. 100–170, corollas 0.2–0.3 mm long; bisexual florets (4–)10–18, corollas 0.6–0.8 mm long. Fruiting heads disintegrating when mature on still-growing plants. Cypselas obloid, narrowly obovoid, or narrowly obcuneoid, 0.8–1.1(1.3) mm long; ribs 2–4, barely raised, with antrorsely appressed hairs; intervening faces lacking vesicular trichomes or very sparse; apex obtuse or rounded (female florets) or truncate (bisexual florets), forming a pale, spongy portion up to a quarter the cypsela length. Flowers mostly Sept.–Nov.