Little Ironweed

Annual herbs, 20–100 cm tall. Stems erect, conspicuously ribbed, sericeous. Leaves 3–5 by 2–3 cm, lanceolate or ovate to broadly ovate, margin undulate to serrate, apex acute to acuminate, base attenuate, chartaceous; upper surface sericeous without glands; lower surface sericeous with cylindrical hairs, T-shaped hairs and capitate glands, lateral veins 5–7-paired; petioles up to 2 cm long. Capitulescences terminal or axillary, paniculate. Capitula campanulate, 5–6 mm long, pedunculate. Receptacle flat, 2–2.5 mm in diam., glabrous. Involucres campanulate, in 3–4 series, 4–4.5 mm long, 2.5–3 mm in diam. Phyllaries imbricate, green with purple apex, margin piliferous, outer surface sericeous glandular; the outer and the middle ones lanceolate, apex acute to acuminate; the inner ones lanceolate to oblong, apex acuminate. Florets 25–30; corollas funnelform, purple or white, puberulous glandular; corolla tubes 3–3.5 mm long; corolla lobes ca. 1 mm long. Anthers ca. 0.6 mm long, apical appendage acute, base obtuse. Styles purple, ca. 3 mm long, branches ca. 0.5 mm long.Achenes clavate, 1.5–1.8 mm long, ribs inconspicuous, densely pubescent with twin hairs and capitate glands. Pappus in 2 series of bristles, the inner ones 3–3.5 mm long, persistent.

Thailand: Mae Hong Son, Chiang Mai, Chiang Rai, Phitsanulok, Nakhon Sawan, Phetchabun, Loei, Nong Bua Lum Phu, Udon Thani, Nong Khai, Sakon Nakhon, Nakhon Phanom, Mukdahan, Kalasin, Maha Sarakham, Khon Kaen, Chaiyaphum, Nakhon Ratchama, Ubon Ratchathani, Kanchanaburi, Lop Buri, Saraburi, Nakhon Nayok, Bangkok, Chumphon, Ranong, Phangnga, Phuket. Tropics and subtropics.