Chaparral Fleabane

Erigeron oreophilus is similar to E. neomexicanus in its perennial habit, typically pinnatifid leaves, white, reflexing rays, and 10–12 readily falling pappus bristles; it has a vestiture of dense, viscid, stipitate glands and sparse, spreading, nonglandular hairs.

Perennials, (8–)25–90 cm; taprooted, caudices woody. Stems erect, sparsely hirsuto-villous (hairs 0.6–2 mm) or glabrous, densely stipitate-glandular (at least on distal ¹ / 2 , glands relatively large, capitate). Leaves basal (sometimes withering by flowering) and cauline; basal blades 15–60 × 8–37 mm, cauline gradually reduced distally, margins deeply pinnatifid, lobes 2–4(–5) pairs, faces usually glabrous, stipitate-glandular. Heads (1–)5–25(–50) in loosely corymbiform arrays. Involucres 4.5–5.5 × 8–12 mm. Phyllaries in 3–4 series, glabrous or sparsely hirsute, densely stipitate-glandular. Ray florets 75–130; corollas white, 8–14 mm, laminae reflexing. Disc corollas 2.8–3.5 mm. Cypselae 1–1.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner (readily falling) of (8–)10–12 bristles. 2n = 18.

Achaetogeron pringlei Larsen; Erigeron delphiniifolius Willdenow var. oreophilus (Greenman) Cronquist

Erigeron oreophilus is a North American species of flowering plant in the family Asteraceae, called the chaparral fleabane. It is native to northern Mexico (Chihuahua, Durango, Sonora) and the southwestern United States (Arizona, New Mexico).

Erigeron oreophilus is a perennial herb up to 90 centimeters (3 feet) tall, with a large taproot. Leaves are pinnatifid with long narrow lobes. The plant generally produces an array of numerous flower heads per stem, each head with up to 75–130 white ray florets surrounding numerous yellow disc florets. The species grows in rocky, open locations in grasslands and conifer woodlands.