Erigeron allocotus Blake

The brittle, hispid vestiture, and multiple small heads (more than one per stem) with short rays of Erigeron allocotus are unusual among its putative relatives with 3-parted leaves.

Perennials, 10–18 cm; taprooted, caudices multicipital or branched. Stems erect to ascending (branched, brittle), hispido-hirsute (hairs brittle), minutely glandular. Leaves basal (often not persistent) and cauline; blades spatulate 15–30 × 1.5–4 mm, cauline gradually reduced distally (reduced to bracts on peduncles), margins usually 3-lobed (lobes linear to oblong-oblanceolate, about as wide as central portion of blades), sometimes 2-ternate or (cauline) entire, faces sparsely hispido-hirsute, minutely glandular. Heads usually 2–4. Involucres 4–5 × 6–9 mm. Phyllaries in 2–3 series, glabrous or sometimes sparsely hispid, densely minutely glandular. Ray florets 20–40; corollas white to bluish, sometimes drying pink, 3–6 mm, laminae not coiling or reflexing. Disc corollas 2.5–3.5 mm. Cypselae 2–2.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12–20 bristles.

Erigeron allocotus is a species of flowering plant in the family Asteraceae known by the common name Bighorn fleabane. It has been found only in the Bighorn Mountains of north-central Wyoming and southern Montana.

Erigeron allocotus is a short, branching shrub rarely more than 18 cm (7 inches) tall. Leaves are 3-lobed. The inflorescence generally consists of 2 or 3 flower heads per stem, each head with sometimes as many as 40 small yellow disc florets and surrounded by a ring of up to 40 white or blue ray florets.

Erigeron allocotus là một loài thực vật có hoa trong họ Cúc. Loài này được S.F.Blake mô tả khoa học đầu tiên năm 1937.