Orobanche californica subsp. grandis
Madroño 22: 60, figs. 1P–R, 3A, 4E. 1973.
Plants simple, rarely branched from base, 8–35 cm, proximal portion to inflorescence (5–) 10–20 cm, stout. Inflorescences corymbs, sometimes subcapitate to subcorymbose racemes, 3–15 cm; bracts pallid to pinkish tinged, drying brown. Pedicels 5–15 (–25) mm. Calyces 12–20 (–25) mm, lobes buff or yellow, tinged pink or brownish, linear-subulate, 15–20 mm. Corollas pallid to pinkish tinged, drying reddish-brown, 35–50 mm; tube broad, abruptly widening toward throat; throat 9–10 mm wide; lips 12–14 mm, abaxial lobes lanceolate to lanceolate-ovate, 5–7 mm wide, apex acute, adaxial lobes ovate, apex obtuse, shallowly notched, erose.
Phenology: Flowering Apr–Oct(–Nov).
Habitat: Sandy soils or lee of foredunes near coast.
Elevation: 0–150 m.
Subspecies grandis is commonly found near the ocean shore from Los Angeles to San Mateo counties and on Santa Rosa Island. It is uncommon, and its habitat is impacted by Carpobrotus (Aizoaceae) invasions. The primary host is Corethrogyne filaginifolia (Asteraceae), but it can also utilize Grindelia (Asteraceae). Other hosts reported are Adenostoma fasciculatum (Rosaceae), Artemisia, Isocoma veneta, and Heterotheca (Asteraceae).
Plants included in subsp. grandis have been identified variously in the past. The northern coastal specimens were aligned with subsp. californica, whereas the southern collections were identified as subspp. feudgei or jepsonii. Subspecies grandis is roughly sympatric with other coastal subspecies, but its unique morphology and its preferences for sand dune habitat and Corethrogyne filaginifolia as a host make it distinctive.