Mem. New York Bot. Gard. 21(4): 46, figs. 6–8. 1971.
Herbs, perennial, 1.8–4(–5) dm; from a woody caudex; with a taproot. Stems several to many, erect to ascending, unbranched, sometimes branched, hairs spreading, long, soft, mixed with shorter stipitate-glandular ones. Leaves green, linear to narrowly or broadly lanceolate, (1–)3–5(–6) cm, not fleshy, margins wavy (obscure on many pressed specimens), involute, usually 0–3(–5)-lobed, apex broadly acute to rounded; lobes widely spreading, linear to narrowly lanceolate, apex acute to acuminate. Inflorescences 2.5–10 × 2–5.5 cm; bracts proximally greenish, distally red to red-orange, narrowly lanceolate to broadly lanceolate, 3–5-lobed; lobes spreading, distal, if present, ascending, linear or narrowly oblanceolate to triangular, proximals long, arising below mid blade, distals short, sometimes mere teeth, near apex of central lobe, sometimes wavy-margined, apex obtuse to rounded, sometimes acute. Calyces whitish with green veins or green, sometimes purple, distally same color as bracts, sometimes with yellowish band below colored apices, 20–26(–29) mm; abaxial clefts (8–)13–16(–19) mm, adaxial 7–12(–14) mm, clefts 35–50% of calyx length, deeper than laterals, lateral 2–6(–8) mm, 10–30% of calyx length; lobes linear-lanceolate to lanceolate, apex obtuse to acute. Corollas straight to slightly curved, 24–38 mm; tube 14–21 mm; beak exserted from calyx, adaxially green, 11–16.5(–18) mm; abaxial lip green, reduced, visible or not through deep front cleft in calyx, 2 mm, 13% as long as beak; teeth incurved, green, 1 mm. 2n = 48.
Phenology: Flowering Jun–Aug.
Habitat: Sagebrush slopes often rocky, montane to subalpine.
Elevation: 1900–3300 m.
Castilleja dissitiflora is endemic to several mountain ranges in central and eastern Nevada, in the upper montane and lower subalpine zones. It has the deep abaxial calyx cleft of C. linariifolia and the stipitate-glandular, wavy-margined leaves of C. applegatei var. pinetorum. Based on morphological data, Holmgren suggested that it is an allopolyploid derived from hybridization of C. applegatei var. pinetorum and C. linariifolia. His proposal is plausible and should be further tested. Castilleja dissitiflora is a tetraploid, while both putative parental species have at least some diploid populations.