Perennials or subshrubs (may flower first year), (20-)30-70+ cm. Cauline leaves ± scattered over proximal ³/4+ of plant heights, internodes mostly 45-95 mm; lobes mostly linear to filiform, sometimes oblanceolate, (5-)15-45(-60) × 0.5-1(-2) mm. Calyculi of 6-8+ linear to subulate bractlets 1-3+ mm. Ray florets usually 8, rarely 0; laminae yellow, 9-15(-20+) mm. Disc corollas yellow with red-brown nerves, throats equal to or longer than lobes. Cypselae 3-4 mm; pappi usually 0, rarely 0.1-0.3+ mm. 2n = 20.

Flowering Apr-Jul(-Oct). Openings in oak/juniper woodlands or desert scrub, usually on limestone; 100-1500 m; Tex.; Mexico (Chihuahua, Coahuila, Nuevo León, Tamaulipas).

Thelesperma simplicifolium is used in roadside plantings and may be encountered as a waif outside its natural range in the flora area (e.g., in California).