Annual herbs, 0.3-1.5 m tall; stems 0.2-0.5 mm diam., glabrous below to copiously stipitate-glandular above with hairs 0.1-0.2 mm long. Leaves narrowly ovate to ovate or deltoid, 4.5-18 cm long, 2.8-13 cm wide, acuminate, the base attenuate, often auriculate at base of petiole, marginally serrate, both surfaces glabrate to strigose with hairs 0.1-0.3 mm long; subsessile or with tapering winged petioles 0.3-6 cm long, to 1 cm wide near blade. Inflorescence with peduncles 3-9 mm long, stipitate-glandular. Heads 3-5 mm tall, 2-3 mm across; involucre of 3 bracts, 2 bracts large, connate and conduplicate around the ray floret, together to 3 mm long and 5 mm wide, with 2 acute lobes, strigillose and stipitate-glandular, the third bract small ovate, 2 mm long, 2 mm wide, the apex acute; paleas 3-5, lanceolate to elliptic, the apex obtuse to rounded, 2 mm long, 0.6-1 mm wide; ray floret 1, the ligule broadly obovate, with 3 deep lobes, 3-5 mm long, 2.5-4 mm wide, resin-dotted on abaxial surface, the tube 0.4 mm long, 0.3 mm diam., glabrous; disc florets 3-5, the corollas green, 1.3 mm diam., the throat 2 mm and tube 1 mm long, glabrous, the anthers black, the ovary filiform, 1.2 mm long, 0.1 mm diam. Achene black, 5 mm long, 3 mm diam., glabrous, enclosed tightly and completely by the 3 bracts which become very leathery at maturity. Chromosome number n = 15.
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