Proc. Amer. Acad. Arts 22: 311. 1887.
Herbs, perennial, 3–5 (–8) dm; from slender, creeping rhizomes. Stems solitary, sometimes few, erect from a slender, creeping base, unbranched, glabrate or hairs spreading, long, soft to ± stiff and shorter, stipitate-glandular. Leaves green, distal sometimes red-tipped, linear-lanceolate, sometimes distal broadly lanceolate or ovate, 1.2–8.9 cm, not fleshy, margins plane, flat or slightly involute, 0–5 (–7) -lobed, apex acute to acuminate, sometimes obtuse or rounded; lateral lobes spreading-ascending or widely spreading, linear, often much narrower than mid-blade, apex acute. Inflorescences 2.5–9 (–11) × 2–5.5 cm; bracts proximally greenish, distally abruptly red to orange-red, often with a yellow, rarely purplish, medial band, narrowly lanceolate to ovate, 3–7 (–11) -lobed; lobes spreading to erect, linear, narrowly lanceolate, or narrowly oblanceolate, long, arising below mid length, apex acute to obtuse. Calyces colored as bracts, 20–30 mm; abaxial and adaxial clefts 11–18 mm, 50–75% of calyx length, deeper than laterals, lateral 8–12 mm, 30–50% of calyx length; lobes linear, apex acute. Corollas ± curved, 30–50 mm; tube 11–18 mm; beak exserted, adaxially green, 18–20 mm; abaxial lip deep green, reduced, 1 mm, 10% as long as beak; teeth ascending, deep green, 1 mm. 2n = 36.
Phenology: Flowering Jun–Sep.
Habitat: Mesic to wet meadows, marshes, peatlands, springs, stream margins, montane to subalpine.
Elevation: 1000–2200 m.
Castilleja suksdorfii is endemic to wet habitats in the Cascade Range from the Goat Rocks Wilderness Area in Yakima County, Washington, south to the vicinity of Crater Lake National Park in Klamath County, Oregon. Reports of this species farther north in Washington and southern British Columbia are referable to C. rupicola. Castilleja suksdorfii is a polyploid species and may be of hybrid origin.
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