Annuals or perennials [shrubs, trees], 7-15+ cm (Verbesina nana) or 30-200(-400)[-2500+] cm. Stems usually erect, usually branched (internodes sometimes winged). Leaves basal and/or cauline; opposite (sometimes whorled) or alternate; petiolate or sessile; blades (pinnately nerved or 3- or 5-nerved from at or near bases) mostly rhombic, deltate, ovate, or elliptic to lanceolate or lance-linear (sometimes intermediate shapes), sometimes pinnately or palmately lobed, bases cuneate to rounded or cordate, ultimate margins subentire or toothed, faces glabrous or hairy. Heads radiate or discoid, borne singly or in corymbiform, dichasiiform, or paniculiform arrays. Involucres hemispheric, turbinate, or campanulate to saucerlike, 5-20+[-30+] mm diam. Phyllaries persistent, 9-30[-50+] in 1-4[-5+] series (orbiculate, ovate, or oblong to spatulate, lanceolate, or linear, subequal or unequal, outer shorter or longer than inner, herbaceous to chartaceous). Receptacles flat to convex or ± conic, paleate (paleae usually navicular, ± conduplicate, herbaceous to scarious, linear to filiform in V. encelioides and V. nana). Ray florets 0 or (1-)5-30, either pistillate and fertile, or styliferous and sterile, or neuter; corollas yellow to orange or ochroleucous [reddish]. Disc florets 8-150[-300+], bisexual, fertile; corollas usually concolorous with rays, tubes much shorter than or ± equaling funnelform or campanulate throats, lobes 5, ± deltate to lance-deltate. Cypselae ± flattened, orbiculate, obovate, or oblanceolate to ± elliptic (usually winged); pappi persistent [falling], usually of 2, ± subulate scales or awns, sometimes 0. x = 17, 18-
Heads radiate, the rays yellow or white, pistillate or neutral, or rarely wanting and the heads discoid; invol of subequal or slightly imbricate, often somewhat herbaceous bracts; receptacle chaffy, shortly conic to sometimes merely polsterform or nearly flat; disk-fls perfect and fertile; style-branches flattened, with papillate or hairy, acute appendage; achenes ±strongly flattened at right angles to the invol bracts, very often winged; pappus mostly of 2 short to well developed awns, occasionally with a few shorter outer scales or minute awns; leaves simple; our spp. herbs. (Actinomeris, Phaethusa, Pterophyton, Ridan, Ximenesia) 60, New World.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.