Plants (0.5-)1-5(-20) dm. Flow-ering stems not fistulose. Inflo-rescences flat-topped, spreading, hemispheric, rarely narrowly erect and strict with whiplike branches. Peduncles absent or deflexed, rarely some ± erect distally, (0.1-)0.2-0.5 cm. Involucres turbinate, 1.5-2.5 mm. Flowers 1-2 mm; outer tepals cordate to ovate. 2n = 40.
Flowering year-round. Sandy to gravelly washes, flats, and slopes, saltbush, creosote bush, greasewood, blackbrush, sagebrush, and mesquite communities, pinyon-juniper woodlands; -50-1900(-2000) m; Ariz., Calif., Nev., N.Mex., Utah; Mexico (Baja California, Sonora).
Variety deflexum is widespread and variable, found mainly in the Mojave and Sonoran deserts of southeastern California, southern Nevada, Arizona, and New Mexico, southward into northern Baja California Norte and northwestern Sonora, Mexico. Plants in southern Arizona tend to have slightly longer peduncles (3-5 mm) and involucres (2-2.5 mm) than do those to the north and west (peduncles 0.1-3 mm, involucres 1.5-2 mm); the former have been recognized as var. turbinatum. Variety deflexum occurs also in the colder Great Basin desert in southwestern Utah, where a sharp distinction between it and var. nevadense is not always possible.