Leiberg's Fleabane

Perennials, 7–25 cm; taprooted, caudices woody, branches usually vertical or horizontal (2–10 cm), sheathed by persistent leaf bases. Stems erect, sparsely to moderately hispidulous to hirsute, minutely glandular to stipitate-glandular. Leaves basal (persistent) and cauline; basal blades sometimes 3-nerved, broadly oblanceolate to obovate or spatulate, 20–90(–120) × 5–25 mm, margins entire or denticulate, faces moderately hirsuto-villous, stipitate-glandular; cauline blades smaller, narrower, relatively even-sized distally (bases subclasping). Heads 1(–5) (on branches from proximal axils). Involucres 5–8 × 7–14 mm. Phyllaries in 2–3 series, sparsely to moderately hirsuto-villous, stipitate-glandular. Ray florets 20–45; corollas usually blue to purplish, sometimes white or pink, 5–12 mm, laminae coiling. Disc corollas 3–4.3 mm. Cypselae flattened, 1.8–2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12–16 bristles.

Erigeron leibergii is a rare species of flowering plant in the family Asteraceae known by the common name Leiberg's fleabane. It is native to the Cascades Mountains in southern British Columbia in Canada and north-central Washington in the United States.

Erigeron leibergii is a branching perennial herb up to 25 centimeters (10 inches) tall, producing a woody taproot. The leaves and the stem are covered with small glandular hairs. The plant can produce 1-5 flower heads per stem, each head with up to 25 purple, lavender, white, or pink ray florets surrounding numerous yellow disc florets in the center.

The species is named for plant collector John Bernhard Leiberg.