Erigeron bellidiastrum Nutt.

Erigeron bellidiastrum is recognized by its annual duration, upcurved hairs of the stem, relatively few rays, 1-seriate pappi, and by some ray florets consistently produced between the phyllaries, the mature cypselae of these held in place as the phyllaries reflex at maturity.

Annuals (or biennials?), 3.5–30(–50) cm; taprooted. Stems erect to ascending, hirsutulous (hairs upcurved), usually eglandular, sometimes minutely glandular (var. arenarius). Leaves basal (sometimes persistent) and cauline or mostly cauline; blades linear to oblanceolate or spatulate, 10–60(–80) × 2–6(–9, or 15) mm, margins entire, lobed, or pinnately dissected, faces sparsely strigose, eglandular. Heads 1–12 usually in diffuse arrays (from branches beyond midstems or sometimes clustered distally). Involucres 3–5 × 5–7(–11) mm. Phyllaries in 2–3(–4) series, hispidulous, minutely glandular. Ray florets 22–70 (some positioned among inner phyllaries); corollas white, often with abaxial lilac midstripe, drying white to bluish, 4–7.5 mm, laminae not coiling or reflexing. Disc corollas 2.2–3 mm (throats indurate and inflated). Cypselae 1–1.6(–1.8) mm, 2-nerved, faces sparsely strigose; pappi: outer cartilaginous crowns, inner of 15–18 bristles.

Erigeron bellidiastrum, the western daisy fleabane or sand fleabane, is a species of fleabane in the family Asteraceae. It is native to northern Mexico (state of Chihuahua) and the western and central United States (western Great Plains and open sandy areas in the deserts west of the Rockies).

Erigeron bellidiastrum is an annual or biennial herb up to 50 cm (20 inches) tall, with a taproot. It produces flower heads in groups of 1–12 on the ends of branches. Each head can have up to 70 white ray florets surrounding many small disc florets.

Varieties Erigeron bellidiastrum var. arenarius (Greene) G.L.Nesom - New Mexico, Texas, Chihuahua). Erigeron bellidiastrum var. bellidiastrum - Arizona, Colorado, Kansas, Montana, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, Utah, Wyoming Erigeron bellidiastrum var. robustus Cronquist - Colorado, Kansas, Nebraska, New Mexico, Oklahoma, Texas