Bull. Torrey Bot. Club 27: 398. 1900.
Herbs, perennial, 0.5–1.5 dm; from a woody caudex; with a taproot. Stems several, decumbent, or ascending, unbranched, hairs moderately dense, spreading, short and long, soft, eglandular and glandular. Leaves green to purple, linear to narrowly lanceolate, 0.7–3.2 cm, not fleshy, margins plane, slightly involute, 3–5-lobed, apex narrowly acute to acuminate; lobes ascending-spreading, narrowly linear to filiform, often curling, often short, apex acute or obtuse. Inflorescences 2.5–6 × 1–2 cm; bracts purple, deep burgundy, or lavender throughout, rarely pink or yellowish white throughout, sometimes pink or dull whitish on distal margins and apices, oblong, 3–5 (–7) -lobed; lobes spreading, linear, medium length, proximal lobes arising below mid length, center lobe apex rounded to obtuse, lateral ones acute to obtuse. Calyces colored as bracts, 10–12 mm; all 4 clefts subequal, 3.5–6.5 mm, 35–55% of calyx length; lobes broadly linear or linear-triangular, apex obtuse to acute. Corollas straight, 12–15 mm; tube 14–16 mm; abaxial lip and beak exserted; beak adaxially green, 5–6 mm; abaxial lip colored as distal portion of bracts, prominent, pouches 3, central one grooved, pouches not strongly inflated, 4–5 mm, 80–100% as long as beak; teeth erect, appressed to beak, colored as distal portions of bracts, 1.5–2.5 mm. Stigmas green.
Phenology: Flowering Jul–Aug.
Habitat: Rocky slopes, ledges, dry to moist gravelly flats and ridges, alpine, limestone, rarely on river cobbles at lower elevations.
Elevation: 2200–3000 m.
Castilleja rubida is a rare alpine species endemic to a few limestone peaks in the Wallowa Mountains of northeastern Oregon, entirely within the Eagle Cap Wilderness Area. It is likely derived from the C. nana complex, found in the mountains of eastern California and Nevada, but it is amply distinct. Due to its very limited range and small population numbers, C. rubida is a species of conservation concern.
"medium" is not a number.