Erigeron disparipilus

Perennials, 3-12 cm; taprooted, caudices branched. Stems erect, densely pilose to hirsute or villoso-hirsute (hairs usually slightly ascending, loose, often mixed in orientations, of unequal lengths, relatively thin-based), eglandular. Leaves mostly basal (persistent), (petioles prominently ciliate, hairs thick-based, spreading); blades linear to linear-oblanceolate, 20-40 × 1-2 mm, margins entire, faces finely hirsute, eglandular; cauline reduced, restricted to proximal ¹ / 3 of stems. Heads 1. Involucres 5-7 × 8-16 mm. Phyllaries in 2-3 series, hirsute to hirsuto-strigose, minutely glandular. Ray florets mostly 30-60; corollas usually white, sometimes fading pink, rarely blue, 5-10 mm, laminae loosely coiling. Disc corollas 2.8-4 mm. Cypselae 1.8-2.2 mm, 2-nerved, faces moderately, loosely strigose; pappi: outer of setae, inner of 15-25 bristles.

Flowering May-Aug. Gravelly and rocky slopes, ridges, sagebrush, grassland; 600-2000(-2200) m; Idaho, Oreg., Wash.

Erigeron disparipilus is similar to E. nanus but less variable. The range of E. disparipilus barely contacts that of E. nanus in southeastern Idaho and they have different ecologies; blue rays of E. disparipilus in Owyhee County may indicate that hybridization occurs.