6. Gutierrezia sarothrae (Pursh) Britton & Rusby, Trans. New York Acad. Sci. 7: 10. 1887.
Solidago sarothrae Pursh, Fl. Amer. Sept. 2: 540. 1813; Xanthocephalum sarothrae (Pursh) Shinners
Subshrubs, 10–60(–100) cm. Stems minutely hispidulous. Leaves: basal and proximal absent at flowering; cauline blades 1- or 3-nerved, linear to lanceolate, sometimes filiform and fascicled, 1.5–2(–3) mm wide, little reduced distally. Heads (sessile to subsessile in compact glomerules) in dense, flat-topped, corymbiform arrays. Involucres cylindric to cuneate-campanulate, 1.5–2(–3) mm diam. Phyllary apices flat. Ray florets (2–)3–8; corollas yellow, 3–5.5 mm. Disc florets (2–)3–9 (usually bisexual and fertile, rarely functionally staminate, corollas tubular-funnelform, lobes erect to spreading or recurved, deltate). Cypselae 0.8–1.6(–2.2) mm, faces without oil cavities, densely strigoso-sericeous; pappi of 1–2 series of narrowly oblong- to ovate-lanceolate or obovate scales (readily falling, those of discs 1 / 3 – 1 / 2 corollas, shorter on rays). 2n = 8, 16, 32.
Flowering Jul–Nov(–Jan). Grasslands, commonly on rocky, open slopes; 50–2900 m; Alta., Man., Sask.; Ariz., Calif., Colo., Idaho, Kans., Minn., Mont., Nebr., Nev., N.Mex., N.Y., N.Dak., Okla., Oreg., S.Dak., Tex., Utah, Wash., Wyo.; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Sonora, Zacatecas).
Gutierrezia sarothrae is often abundant in overgrazed pastures; it is naturalized in New York.