Castilleja angustifolia var. dubia
Bull. Torrey Bot. Club 29: 404. 1902.
Stems: hairs fairly dense, spreading, short and long, soft to stiff, eglandular. Bracts distally yellow to pale orange or white, sometimes red, 3–9-lobed, sometimes with secondary lobes. Calyces 18–22 mm; abaxial clefts 5–7 mm, adaxial 7–8 mm. Corollas 18–27 mm.
Phenology: Flowering Jun.
Habitat: Dry sagebrush slopes and flats in mountains, high plains.
Elevation: 1500–2400 m.
Variety dubia is often confused with Castilleja chromosa in herbaria, floras, and databases, but they are not synonymous. Where C. angustifolia and C. chromosa are sympatric in Wyoming, the specimens show little evidence of hybridization. Variety dubia, found primarily in southwestern South Dakota and east-central Wyoming, can be recognized by its usually narrower, yellow to pale orange inflorescences, as well as by its shorter corollas, while C. chromosa has wider, red inflorescences and longer corollas. Occasional hybrids between var. dubia and C. sessiliflora are known from northeastern Wyoming.