Linnaea 3: 134. 1828.
Plants simple or branched proximally, 4–35 (–40) cm, slender or stout, base sometimes enlarged. Roots inconspicuous (rarely forming a bulbous mass), slender or stout, unbranched, sometimes branched (subsp. grandis). Leaves numerous, appressed; blade broadly ovate, triangular, deltate, lanceolate, or oblong, 4–12 mm, margins entire or erosulate, apex obtuse or rounded, surfaces glabrous. Inflorescences corymbs (sometimes subcapitate), sometimes racemes or subcorymbose racemes, dark purple, reddish purple, pinkish, or pallid cream to nearly white, simple, sometimes inconspicuously branched, densely glandular-puberulent; flowers numerous (rarely 10 or fewer in depauperate plants); bracts appressed to spreading, ± lanceolate to oblanceolate, 5–15 mm, apex acute, glandular-pubescent. Pedicels 0–20 (–25) mm, shorter than plant axis; bracteoles 2. Flowers: calyx pallid to dark purple, pink, yellow, or white, ± weakly bilaterally symmetric, 8–20 (–27) mm, deeply divided into 5 (sometimes reflexed or contorted) lobes, lobes subulate to linear-subulate, gradually attenuate, glandular-pubescent; corolla 22–50 (–55) mm, tube white or cream to pinkish or purplish tinged or pink to purple, sometimes with darker veins, constricted above ovary, curved forward, sparsely to moderately glandular-puberulent; palatal folds prominent, yellow, glabrous (lacking blisterlike swellings), sometimes pubescent; lips white or cream to pinkish or purplish tinged (then sometimes appearing reddish-brown in herbarium specimens) or pink to purple, sometimes with darker veins or dark purple distally, abaxial lip widely spreading, 8–15 mm, lobes ± lanceolate to ± oblong, lanceolate-subulate, narrowly triangular, or lanceolate-ovate, apex ± acute to rounded or obtuse, sometimes retuse or emarginate, adaxial lip ± spreading, 10–15 (–18) mm, lobes broadly deltate to ovate or oblong, apex bluntly pointed to rounded, obtuse, acute, shallowly retuse, erosulate, emarginate, shallowly notched, or erose; filaments glabrous, anthers included, densely villous on sutures, rarely glabrous. Capsules ovoid to cylindric-ovoid, 10–12 mm. Seeds 0.4–0.6 mm.
B.C., Calif., Oreg., Wash., nw Mexico
Subspecies 6 (6 in the flora).
Plants of Orobanche californica occur almost entirely in and west of the Cascade-Sierra Nevada-Peninsular ranges from British Columbia south to the Sierra San Pedro Mártir in Baja California. Host plants are various perennial members of Asteraceae.
L. R. Heckard (1973) discussed the difficulty of presenting a classification for Orobanche californica based on the few morphological features that must be used for taxonomic delineation and the sometimes baffling disjunctions in the distribution of the variants. He recognized six subspecies based on geographic variations that demonstrate the considerable variability within the species. The following key to subspecies is adapted from the key by Heckard.
|1||Corollas dark purple or red-purple distally; calyx lobes and bracts purple tinged, drying blackish purple.||Orobanche californica subsp. californica|
|1||Corollas pallid, pinkish, pale lavender, whitish, or yellowish distally, often with darker veins; calyx lobes pallid, pinkish tinged, whitish, yellow, or buff, sometimes purplish or tinged pinkish, purple, or brownish, bracts pallid to pinkish tinged, drying brown.||> 2|
|2||Corolla tubes gradually widening toward throat, corollas pallid or yellow distally, sometimes pinkish tinged.||Orobanche californica subsp. feudgei|
|2||Corolla tubes abruptly widening toward throat, corollas pallid, pale pink, or pale lavender, sometimes yellowish tinged distally.||> 3|
|3||Corollas 35–50 mm, abaxial lobes lanceolate to lanceolate-ovate, 5–7 mm wide.||Orobanche californica subsp. grandis|
|3||Corollas 25–35(–40) mm, abaxial lobes lanceolate to lanceolate-subulate, narrowly lanceolate, or lanceolate-oblong to narrowly triangular, 2–4(–5) mm wide.||> 4|
|4||Plants (8–)10–35 cm, portions proximal to inflorescences 6–15 cm; inflorescences racemes, sometimes subcorymbose, 5–20 cm.||Orobanche californica subsp. jepsonii|
|4||Plants 4–10(–15) cm, portions proximal to inflorescences 1–8(–12) cm; inflorescences corymbs, sometimes subcorymbose or subcapitate racemes, 2–6 cm.||> 5|
|5||Plants: portions proximal to inflorescences 1–3(–4) cm; abaxial corolla lobes lanceolate to lanceolate-subulate, 2–3 mm wide, apices acute.||Orobanche californica subsp. grayana|
|5||Plants: portions proximal to inflorescences 3–8(–12) cm; abaxial corolla lobes lanceolate-oblong to narrowly triangular, 3–4 mm wide, apices bluntly acute or obtuse, sometimes retuse or emarginate.||Orobanche californica subsp. condensa|