Astranthium robustum (Shinners) De Jong

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.