Phytologia 72: 210. 1992. (as genevievana)
Herbs, perennial, 1.5–4.5 dm; from a woody caudex; with a taproot. Stems several, erect or ascending, unbranched or often branched proximally, loosely lanate, hairs spreading to retrorse, flattened, often matted, long, soft, eglandular. Leaves green to gray-green, linear-lanceolate to narrowly oblong, 1.5–7.5 cm, not fleshy, margins plane, involute, 0(–3)-lobed, apex rounded; lobes spreading, linear or filiform, originating from distal 1/3 of blade, apex acute. Inflorescences 2.5–10(–20 in fruit) × 1.5–2.5 cm; bracts proximally pale greenish to green, distally yellow, yellow-orange, or orange, ovate to broadly lanceolate or broadly oblanceolate-obovate, 0–3-lobed; lobes ascending to erect, narrowly lanceolate, medium length, arising near or above mid length, apex rounded to acute. Calyces colored as bracts, 23–27 mm; abaxial and adaxial clefts 10–15 mm, 33–50% of calyx length, deeper than laterals, lateral 4–9 mm, 15–33% of calyx length; lobes oblong to lanceolate or narrowly triangular, apex acute to rounded. Corollas straight or slightly curved, 24–37 mm; tube 15–22 mm; slightly shorter than calyx or usually with beak, sometimes abaxial lip, exserted beyond calyx apices; beak adaxially green to yellowish, 7–15 mm; abaxial lip green or yellowish, reduced, ± inconspicuous, slightly pouched, 1.6–6 mm, less than 50% as long as beak; teeth spreading, yellow or yellow-green, 1–4 mm.
Phenology: Flowering Mar–Jun.
Habitat: Rocky slopes, open stands of juniper, over limestone.
Elevation: 500–900 m.
Tex., Mexico (Coahuila).
Castilleja genevieveana is known from eight counties in southwestern Texas and from a small area of adjacent Coahuila, Mexico. The species is likely related to the widespread C. integra and geographically replaces it.