Perennials, 15-28 cm; taprooted (root or caudex branches 1-4 cm, rhizomelike or caudexlike). Stems decumbent-ascending (distal branches spreading-ascending, axillary tufts of smaller leaves prominent at most nodes), sparsely to moderately strigose (hairs ascending-appressed), eglandular. Leaves cauline; blades oblanceolate, (25-)30-45 × (2-)5-8 mm, reduced near heads, margins entire, faces sparsely to moderately strigose, eglandular. Heads 1 or 2-4 (in loosely corymbiform arrays). Involucres mostly 4-5 × 8-12 mm. Phyllaries in 3-5 series, outer (midnerves prominently orange-resinous) sparsely strigose (hairs thin-based), eglandular (inner: margins broadly scarious, nearly winglike). Ray florets 18-22; corollas bluish, 5-8 mm, laminae sometimes coiling slightly at tips. Disc corollas 4-4.5 mm (throats slightly indurate, not inflated). Cypselae 2-2.4 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 28-32 bristles.

Flowering Jun-Aug. Foothill woodlands, substrate unknown; of conservation concern; 600-800 m; Calif.

Erigeron mariposanus is closely similar to E. aequifolius.