Plants 6-15 cm (forming mats on rock faces, profusely branched, leafy); short-hairy. Leaves: petioles 4-8 mm; blades ± ovate to deltate overall, 5-12 × 5-12 mm, 3-lobed, ultimate margins entire. Heads borne singly or in corym-biform arrays, 6-7 × ca. 4 mm. Peduncles 2-5 mm. Involucres funnelform-cylindric. Phyllaries ca. 8, linear-lanceolate, 5-6 × 0.8-1.3 mm. Disc florets ca. 10; corollas cream to pale yellow, tubes 1 mm, throats tubular-funnelform, 3 mm, lobes 0.5 mm. Cypselae 1.5-1.6 mm; pappi of ca. 20 bristles 1-2 mm. 2n = 34. Flowering spring-fall. Rock faces in protected canyons; of conservation concern; 1500-1660 m; Tex. Perityle fosteri, possibly a close relative of P. rupestris, is known only from Culberson County.