Fl. Bor.-Amer. 2: 110. 1838
Plants 10–50 cm. Leaves: basal 1–10, blade lanceolate, 30–200 x 20–70 mm, 2(or 3)-pinnatifid, margins of adjacent lobes nonoverlapping or extensively overlapping distally, 1-serrate, surfaces glabrous, hispid, or downy; cauline 4–20, blade lanceolate, 15–250 x 5–100 mm, 2-pinnatifid, margins of adjacent lobes nonoverlapping or extensively overlapping distally, serrate, surfaces glabrous, hispid, or downy. Racemes simple, 1–5, exceeding basal leaves, each 10–50-flowered; bracts lanceolate to trullate, 10–35 x 3–5 mm, undivided or 1-pinnatifid, proximal margins entire, distal 1- or 2-serrate, surfaces glabrous. Pedicels 2–4 mm. Flowers: calyx 9–18 mm, downy to tomentose, lobes 5, triangular, 3–4 mm, apex entire, ciliate; corolla 23–43 mm, tube dark red, purple, or orange-yellow, rarely white, 8–18 mm; galea dark red, purple, or orange-yellow, rarely white, 15–25 mm, beakless, margins entire medially and distally, apex straight; abaxial lip dark red, purple, or orange-yellow, rarely white, 8–15 mm. 2n = 16.
Phenology: Flowering Feb–May.
Habitat: Mixed coniferous forests.
Elevation: 30–3100 m.
Calif., Oreg., Mexico (Baja California).
Scarlet corollas with an undomed, toothless galea and two- or three-pinnatifid leaves are diagnostic of Pedicularis densiflora. This species occurs in forested subalpine regions of southern Oregon, western slopes of the Sierra Nevada, and the Coast Ranges of California south to Baja California. Herbarium records indicate northern populations of P. densiflora occur at higher elevations than do more southern populations.