Arizona Fleabane

Perennials, 8–40(–60) cm; rhizomatous, fibrous-rooted, caudices or rhizomes relatively thick, simple or branched, sometimes resembling a taproot. Stems erect to basally ascending, moderately to densely strigose to strigoso-hirsute or hirsute, eglandular. Leaves basal (commonly persistent) and cauline; basal blades often 3-nerved, spatulate, obovate to ovate, or elliptic, 20–150 × 5–25 mm, margins entire to shallowly serrate, faces loosely strigose, rarely minutely glandular; cauline blades slightly smaller than basal, relatively even-sized to peduncle bases, (bases subclasping) margins entire, becoming lanceolate (bases non-clasping) distally. Heads 1–4(–6) (from branches on distal ¹ / 3 – ¹ / 2 of stem, peduncles distinct, 1.5–9 cm). Involucres 5–7 × 9–18 mm. Phyllaries in 3–4 series (greenish), moderately piloso-hirsute, densely minutely glandular (sometimes obscured by hairs). Ray florets 25–80; corollas white, drying white or lilac-tinged, 8–10 mm (ca. 1 mm wide), laminae coiling at tips. Disc corollas 2.9–4 mm. Cypselae 1.6–2.1 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 15–26 bristles. 2n = 18.

Erigeron rusbyi A. Gray

Erigeron arizonicus is a species of flowering plant in the family Asteraceae known by the common name Arizona fleabane. It is native to the southwestern United States (Arizona, New Mexico) and northwestern Mexico (Sonora).

Erigeron arizonicus is a perennial herb up to 60 cm (2 feet) tall, spreading by means of underground rhizomes. It produces 1-6 flower heads per branch, each head containing 25–80 white ray florets and many small yellow disc florets.

Erigeron arizonicus là một loài thực vật có hoa trong họ Cúc. Loài này được A.Gray mô tả khoa học đầu tiên năm 1883.