Nov. Pl. Descr. Dec., 39, plate 4. 1797.
Perennials, 30–100 cm (rhizomatous). Stems erect, branched ± throughout. Leaves cauline; opposite; petiolate or sessile; blades (3-nerved) lanceolate to lance-linear (widest at or proximal to middles, not notably fleshy), bases cuneate, margins entire or toothed, faces sparsely scabrous. Heads radiate, borne singly. Involucres campanulate to hemispheric, 10–15 mm diam. Phyllaries persistent, 20–28 in 2–3 series (linear to lance-linear, herbaceous, subequal or outer longer than inner, spreading in fruit). Receptacles hemispheric, paleate (paleae lanceolate to ovate, conduplicate, becoming papery). Ray florets 13–21, pistillate, fertile; corollas yellow. Disc florets 45–90+, bisexual, fertile; corollas yellow, tubes shorter than campanulate throats, lobes 5, ± deltate. Cypselae 3-angled or ± compressed and weakly 4-angled (epidermes usually thick, corky, bases without elaiosomes, apices not rostrate); pappi 0, or persistent, coroniform (of connate scales plus 0–2 awns). x = 33.
Introduced; South America.
Species 2 (1 in the flora).