Foster’s rock daisy

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.