Annuals, 5-50 cm (taprooted); herbage spicy-scented. Stems erect or ascending, glabrous or sparsely puberulent (in decurrent lines). Leaves linear to narrowly elliptic, 10-50 × 1-5 mm, margins with 1-3 pairs of setae, faces glabrous or sparsely puberulent (dotted on margins with round oil-glands 0.2-0.7 mm). Heads borne singly or in open, cymiform arrays. Peduncles 20-80 mm. Involucres campanulate. Phyllaries distinct, oblong or narrowly obovate, 4-7 × 1-2 mm (dotted with 0-2, subterminal oil-glands plus 2-4 pairs of inconspicuous, round to narrowly elliptic, submarginal oil-glands). Ray florets 8(-13); corollas 5-11 mm. Disc florets (7-)20-55; corollas 3.5-5 mm (2-lipped). Cypselae 3-4.5 mm, strigillose or short-pilose; ray pappi of 1-4, antrorsely barbed awns 1-4 mm or coroniform; disc pappi of 15-30, antrorsely barbed bristles 2.5-5 mm or coroniform. 2n = 24 (as P. palmeri). Flowering Jul-Oct. Deserts, desert grasslands, arid scrub, dry woodlands; 600-1600 m; Ariz.; Mexico (Baja California Sur, Sinaloa, Sonora). Pectis rusbyi is much less common in Arizona than P. papposa var. papposa, with which it sometimes grows.