Erigeron disparipilus
Brittonia 6: 194. 1947.
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.
Phenology: Flowering May–Aug.
Habitat: Gravelly and rocky slopes, ridges, sagebrush, grassland
Elevation: 600–2000(–2200) m
Distribution
Idaho, Oreg., Wash.
Discussion
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.
Selected References
None.