Herbs, perennial, 2.5–5 dm; from a woody caudex; with a taproot. Stems few to several, ascending to erect, unbranched or branched distally, sometimes with a few small, leafy axillary shoots, hairs spreading, long, soft, eglandular. Leaves green to purple-tinged, sometimes purple, narrowly to broadly lanceolate, 2.5–5 cm, not fleshy, margins plane, sometimes ± wavy, flat, 0(–5)-lobed, apex acuminate; lobes ascending-spreading, linear to narrowly lanceolate, apex acute. Inflorescences 3–15 × 2–4 cm; bracts proximally greenish, distally yellow-green, green, pale yellow, cream, or pale orange, often tinged with bright orange along margins, aging dull pink, broadly lanceolate to oblong or obovate, (0–)3–5(–7)-lobed; lobes ascending to erect, linear to narrowly lanceolate, medium length, arising above or below mid length, central lobe apex rounded to obtuse, lateral ones usually acute. Calyces colored as bracts, 13–20 mm; abaxial and adaxial clefts 5–9 mm, 33–50% of calyx length, deeper than laterals, lateral 1–2 mm, 7–25% of calyx length; lobes oblong, apex acute to rounded. Corollas straight, (15–)17–27 mm; tube 11–12 mm; beak exserted, adaxially green, 9–10 mm; abaxial lip green, reduced, visible in front cleft, 0.5–2 mm, 10–20% as long as beak; teeth incurved to erect, green, 0.5–1 mm. 2n = 24, 48.
Phenology: Flowering Jun–Sep. Habitat: Subalpine wet meadows and springs, mixed conifer forests, volcanic soils. Elevation: 2600–2900 m.
Discussion: Castilleja mogollonica is endemic to the Mogollon Rim in the White Mountains of Apache County. It is frequently confused with the widespread C. septentrionalis but is amply distinct therefrom. This species faces threats from grazing, road building, and recreational activities. It occasionally hybridizes with C. nelsonii.