298. Simsia Persoon, Syn. Pl. 2: 478. 1807.
Bush sunflower [For John Sims, 1749–1831, British physician and botanist]
David M. Spooner
Annuals, perennials, or subshrubs [shrubs], 20–400 cm. Stems erect or ascending [decumbent], sparingly to freely branched. Leaves cauline; opposite (proximal) or alternate [whorled]; petiolate (petioles often ± winged, often with expanded bases, those bases sometimes fused to form nodal "discs") [sessile]; blades 3-nerved from bases, mostly deltate to ovate [linear], sometimes 3- [5-]lobed[pinnatifid], bases cordate to cuneate, ultimate margins entire or toothed, faces hirsute, hispid, pilose, puberulent, scabrous, or scabro-hispid [sericeous], often gland-dotted or ± stipitate-glandular to glandular-puberulent. Heads radiate [discoid], borne singly or in 2s or 3s, or in tight to loose, corymbiform [paniculiform] arrays. Involucres campanulate [ovoid-campanulate to urceolate], 5–16[–22] mm diam. Phyllaries persistent, [11–]13–43[–66] in 2–4 series (tightly appressed to broadly reflexed, unequal to subequal). Receptacles low-convex, paleate (paleae conduplicate, ± enclosing cypselae). Ray florets [0–]5–21[–45], styliferous and sterile; corollas orange-yellow [lemon-yellow, pink, purple, or white]. Disc florets [12–]13–154[–172], bisexual, fertile; corollas concolorous with rays (usually turning purple apically), tubes (often glandular-hairy) shorter than throats, lobes 5, ± triangular (anthers black, yellow, or yellow proximally and bronze or purple distally; style branches relatively slender, apices sometimes attenuate). Cypselae flattened, thin-margined [thickened, biconvex] (shoulders minute to conspicuous, faces glabrous or hairy); pappi 0, or fragile or readily falling, of 2 ± subulate scales [plus 4–12 shorter scales]. x = 17.
Species 20 (2 in the flora): sw United States, Mexico, West Indies (Jamaica), Central America, South America.
Spooner, D. M. 1990. Systematics of Simsia (Compositae–Heliantheae). Syst. Bot. Monogr. 30: 1–90.