Shrubs, 10-40(-60+) cm. Stems erect. Leaves mostly alternate; petioles 2-8(-12+) mm; blades (white) ovate to elliptic, 10-25(-45) × 8-15(-30) mm, (1-)2-3-pinnately lobed, abaxial and adaxial faces densely strigillose. Pistillate heads intermixed with staminates (sometimes wanting or staminates sometimes wanting, plants unisexual); florets (1-)2. Staminate heads: peduncles 0-1(-2) mm; involucres shallowly cup-shaped, 3-5 mm diam., ± strigillose; florets 8-15+. Burs: bodies ± globose, 3-5+ mm, pilosulous and/or gland-dotted, spines 12-25+, scattered, ± subulate (± navicular at bases), 2-4 mm, tips straight. 2n = 36, 72, 108, 126. Flowering Mar-May(-Dec). Rocky or sandy washes, benches; (-100-)100-1200(-1500) m; Ariz., Calif., Nev., Utah; Mexico (Baja California, Sonora).

Plant: Shrub 2-9 dm, much-branched; stems softly gray-white canescent Leaves: opposite below, generally alternate above, petioled, hairy, glandular, generally ± clustered on short branches, (sub)sessile; blade 0.5-4 cm, ± ovate, 1-3-pinnate, canescent INFLORESCENCE: primary inflorescence a head, each resembling a flower; staminate heads generally many in ± spikes or racemes, 3-5 mm diam; involucre lobes 5-8; pistillate heads 2-flowered; receptacle chaffy; chaff scales spirally arrayed, fused below, tips generally becoming spiny Flowers: Staminate flowers ± many; corolla yellow or translucent; anthers free; style unbranched; Pistillate flowers 1-5; corolla 0; style branches long Fruit: Fruit: enclosed in a bur 5-9 mm, spheric, golden to purple or brown, puberulent; spines 12-35, scattered, straight, flat, sharp Misc: Creosote-bush scrub; < 1600 m.; Feb-Jun, Sep-Nov Notes: receptacle envelopes pistils in spiny covering References: J.C. Hickman, ed. The Jepson Manual.L. Benson & R. Darrow. Trees and Shrubs of the Southwestern Deserts. Kearney & Peebles. Arizona Flora. ASU specimens.