52. Brickellia Elliott

Plants perennial, often with thickened roots. Stems solitary to several, erect or ascending, usually sparsely to densely pubescent with short, curly or curved hairs. Leaves alternate or opposite (the nodes usually well separated), sessile to long-petiolate, the basal leaves usually absent at flowering, when present then about as large as or smaller than the lower and median stem leaves. Leaf blades linear to ovate-triangular or nearly heart-shaped, tapered, angled, truncate, or cordate at the base, usually tapered to a sharply pointed tip, the surfaces variously short-hairy to glabrous or nearly so, at least the undersurface also glandular, with (1)3(5) main veins. Inflorescences panicles, sometimes reduced to stalked clusters at the branch tips, flat-topped to dome-shaped, or less commonly appearing as a leafy panicle with racemose branches. Heads with 6–40 disc florets. Involucre narrowly cup-shaped to narrowly bell-shaped, the bracts 22–35 (the head often also subtended by 1 or more other shorter bracts) in usually several unequal, overlapping series, the bracts linear to narrowly oblong-elliptic or narrowly oblanceolate, those of the outer series sometimes ovate, tapered or narrowed to a bluntly or sharply pointed tip, glabrous or sparsely to moderately and finely short-hairy, also glandular. Receptacle flat or nearly so. Corollas cream-colored to greenish yellow. Pappus of 20–25 bristles, these minutely barbed or plumose. Fruits 1.7–5.0 mm long, (8–)10-nerved or ribbed, slightly wedge-shaped in profile (usually slightly and unevenly tapered at the base) to nearly linear, usually minutely hairy, brown to dark brown. About 100 species, North America, Central America, South America, most diverse in the U.S. and Mexico.