1. Grindelia ciliata (Nuttall) Sprengel, Syst. Veg. 3: 575. 1826.
Donia ciliata Nuttall, J. Acad. Nat. Sci. Philadelphia 2: 118. 1821; Grindelia papposa G. L. Nesom & Y. B. Suh; Haplopappus ciliatus (Nuttall) de Candolle; Prionopsis ciliata (Nuttall) Nuttall
Annuals or biennials, 20–150+ cm. Stems erect, stramineous, glabrous (branched distally). Cauline leaf blades oblong to obovate, 30–50(–80) mm, lengths mostly 2–4 times widths, bases ± clasping, margins dentate (teeth apiculate to setose), apices rounded, faces glabrous, obscurely, if at all, gland-dotted. Heads borne singly or in open to crowded, corymbiform arrays. Involucres broadly urceolate, 10–15 × 15–25 mm. Phyllaries in 3–5 series, spreading to appressed, subulate to linear-lanceolate, apices recurved to straight, attenuate, slightly to moderately resinous. Ray florets 25–45; laminae 10–15+ mm. Cypselae whitish to grayish, 2–4 mm, apices smooth or minutely coronate, faces smooth or striate; pappi (persistent or tardily falling) of 25–40 barbellate bristles 3–7+ mm subtending 8–15+ barbellate, setiform awns or subulate scales 7–10 mm (the longer surpassing disc corollas). 2n = 12.
Flowering Aug–Oct. Disturbed sites, prairies, railroads, roadsides; 100–1500 m; Ariz., Ark., Calif., Colo., Ill., Iowa, Kans., La., Mich., Mo., Nebr., N.Mex., Okla., Tex.