1. Gaillardia pinnatifida Torrey, Ann. Lyceum Nat. Hist. New York. 2: 214. 1827.
Gaillardia flava Rydberg; G. gracilis A. Nelson; G. mearnsii Rydberg; G. pinnatifida var. linearis (Rydberg) Biddulph
Perennials (sometimes flowering first year, sometimes rhizomatous), (5–)15–35+ cm. Leaves basal and cauline, mostly re-stricted to proximal 1/3–1/2; petiolar bases 0–5+ cm; blades mostly oblanceolate to spatulate, 3–6(–12) cm × 3–18(–30) mm, margins mostly pinnatifid, distal sometimes toothed or entire (rarely all linear, entire), faces closely strigillose to shaggily villous. Peduncles (4–)8–25+ cm. Phyllaries 20–30, ovate- to lanceolate-attenuate, 7–12+ mm, hispidulous to villous (hairs often jointed). Receptacular setae usually 1–3 mm, rarely wanting. Ray florets 0 or 5–14; corollas usually uniformly yellow, sometimes proximally and/or abaxially reddish, 10–25+ mm. Disc florets (30–)60–100+; corollas usually proximally ochroleucous or yellow and distally purplish, rarely wholly yellow, tubes 0.8–1 mm, throats campanulate to plumply urceolate, 3–4.5 mm, lobes broadly deltate to deltate-ovate, 0.5–1 mm, jointed hairs 0.3+ mm. Cypselae obpyramidal, 1–3 mm, hairs 1–2 mm, inserted at bases and on angles and faces; pappi of 8–11 lanceolate, aristate scales 3–7 mm (scarious bases 1.5–4 × 0.5–1.5 mm). 2n = 34.
Flowering Mar–Oct, mostly May–Jul. Clays or sandy soils, often disturbed places, in grasslands, desert scrub-lands, or pinyon woodlands; 900–2000 m; Ariz., Colo., Nev., N.Mex., Okla., Tex., Utah; Mexico (Chihuahua, Coahuila, Durango, Sonora).
Some plants, especially from Arizona, included here in Gaillardia pinnatifida, have mostly narrow, undivided leaf blades (mostly 3–8+ mm wide, villous to sparsely strigillose; var. linearis) and intergrade with similar plants called G. multiceps, which have sparsely and minutely hispidulous or glabrate leaf blades.
Plants from Utah with yellow disc corollas and densely gland-dotted leaves, included here in Gaillardia pinnatifida, have been recognized as G. flava.