Proc. Acad. Nat. Sci. Philadelphia 99: 183. 1947.
Herbs, perennial, 1–9 dm; from a woody caudex; with a taproot. Stems few-to-many, usually decumbent proximally, becoming ascending-erect, sometimes ascending, branched, sometimes with small, leafy axillary shoots, glabrate or ± pubescent distally, hairs sparse to moderately dense, spreading to ± appressed, short, soft, sometimes mixed with short-glandular ones below inflorescence. Leaves green, lanceolate to oblong or narrowly ovate, (0.5–) 3–8 cm, sometimes thickened, not fleshy, margins plane, sometimes ± wavy, flat to involute, 0 (–3) -lobed, apex acute to rounded; lobes ascending or spreading, linear, narrowly lanceolate to oblong or triangular, short, apex acute to obtuse. Inflorescences 2.5–21 × 3–5 cm; bracts proximally green, distally bright red to crimson or orange-red, sometimes orange or pale yellow-orange, oblong to narrowly ovate or narrowly obovate, (0–) 3–5-lobed, sometimes with a pair of small teeth; lobes ascending, linear to oblong, medium length, arising in middle 1/3, central lobe apex obtuse to rounded or truncate, lateral ones ± acute. Pedicels 0–6 mm. Calyces colored as bracts, 17–25 (–30) mm; abaxial and adaxial clefts (5–) 7–15 (–18) mm, 33–55% of calyx length, deeper than laterals, lateral 1–3 (–5) mm, 5–10% of calyx length; lobes broadly triangular to oblong, apex obtuse to acute or rounded. Corollas straight or slightly curved, 23–38 (–40) mm; tube 10–20 mm; abaxial lip often visible through front cleft, very rarely almost exserted, beak exserted; beak adaxially green or yellowish, 10–16 mm, surface inconspicuously puberulent; abaxial lip ascending, green, reduced, 1–2.5 mm, 10–20% as long as beak; teeth erect or incurved, green or white, 1–2 mm. 2n = 120, 144.
Phenology: Flowering (Apr–)May–Aug(–Sep).
Habitat: Steep rocky slopes, headlands, ledges, sea cliffs, coastal scrub, dune swales, roadcuts.
Elevation: 0–200 m.
Calif., Oreg., Wash.
Castilleja litoralis never ranges more than one to two kilometers from the sea, from Humboldt County, California, north to Pacific County, Washington, near the mouth of the Columbia River. It is a high polyploid complex, possibly incorporating the genomes of several species, including C. affinis, C. miniata, and possibly C. hispida. The coastal C. miniata var. dixonii is very similar ecologically and morphologically but replaces C. litoralis from southwestern Washington to southern British Columbia. Compared to C. litoralis, C. miniata var. dixonii usually has somewhat longer corollas and corolla beaks, the latter with a more conspicuously puberulent surface and deeper lateral calyx clefts. Castilleja litoralis has been included as a subspecies of C. affinis by some (for example, M. Wetherwax et al. 2012), but the morphological resemblance to that species is far more tenuous than it is to C. miniata var. dixonii. Considering their very similar morphologies, along with the fact that both C. litoralis (2n = 120, 144) and C. miniata var. dixonii (2n = 96, 144) apparently combine multiple genomes, strongly suggest that they would best be treated as a single entity. Should they be combined at the species level following additional research, the name C. dixonii has priority.
Castilleja litoralis is often associated with salal, Gaultheria shallon, on which it is likely parasitic.
"medium" is not a number.