Annuals, taprooted. Stems usually 3-8, decumbent-ascending, sometimes 1, erect. Leaves: basal and proximal cauline 20-45 × 5-11 mm. Involucres 4-6.8 mm. Ray florets 18-35; corolla laminae white or abaxially lavender, often drying pinkish, 8-13 mm. Disc floret corollas 3.2-3.8 mm. Cypselae 1.4-2.1 × 0.7-1.2 mm, faces minutely, glandular-papillate-pebbly, uniformly sparsely to moderately glochidiate-hairy. 2n = 6.

Flowering Mar-Jun. Disturbed sites in sandy or rocky soil, mesas, canyons, pine flats, roadsides, ditches; 800-1400 m; Tex.

Astranthium robustum is known only from the trans-Pecos region.