Perennials, 5-60 cm (colonial); taprooted, caudex branches rhizomelike plants. Stems (often purplish) erect or decumbent at bases, sparsely strigillose (basal cells inclined, hairs even-width), eglandular. Leaves basal (often withering by flowering) and cauline; basal blades linear to narrowly oblanceolate, 50-120(-180) × 3-6(-11) mm, cauline 3-nerved, gradually reduced distally, margins entire, faces hirtellous, eglandular. Heads (1-)2-5(-18) borne singly or in loosely corymbiform arrays. Involucres (4.5-)5-6 × 9-12 mm. Phyllaries in 2-3(-4) series (linear-lanceolate, apices linear-acuminate), sparsely to moderately villous, eglandular. Ray florets 26-57; corollas white to bluish, sometimes drying pinkish to pale blue, 7-12 mm, laminae not coiling or reflexing. Disc corollas 3-3.5 mm. Cypselae 1.2-1.6 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae , inner of (6-)12-16 bristles.

Flowering May-Jul. Heavy soils in seasonally wet or dry upland prairie grasslands; of conservation concern; 100-300 m; Oreg.

Erigeron decumbens is in the Center for Plant Conservation´s National Collection of Endangered Plants.