Perennials, 7-25 cm; taprooted, caudices branched. Stems sprawling or pendent (branched), hirsute, minutely glandular. Leaves cauline; blades cuneate to obovate, 150-400 × 10-20 mm, nearly even-sized to near heads, margins 3-lobed or -dentate (lobes sometimes with shallow secondary lobes or teeth, much narrower than central portion of blades, usually acute), faces hirsute, minutely glandular. Heads 1-4 (from medial or distal branches). Involucres 5-6 × 8-12 mm. Phyllaries in 2-3 series, usually densely villoso-hirsute, densely minutely glandular. Ray florets 22-30; corollas white, drying pink to pinkish purple, 5-7 mm, laminae not coiling or reflexing. Disc corollas 3-4 mm. Cypselae ca. 1.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 10-15 bristles.

Flowering May-Jun(-Oct). Dry, vertical, basalt cliffs of Yakima River and tributaries; of conservation concern; 300-500 m; Wash.

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