Orobanche cooperi subsp. cooperi
Plants simple or branched, base sometimes enlarged. Leaves sometimes imbricate proximally; blade broadly lanceolate, 7–11 mm, apex obtuse. Inflorescences: bracts 8–11 (–13) mm, apex not or only slightly reflexed. Corollas (15–) 18–22 mm; palatal folds pubescent; abaxial lip 4–7 mm, adaxial lip erect, 5–9 mm, lobes with or without apiculate tooth. Anthers glabrous or sparsely villous, stalked glands present on dorsal surface, sometimes obscure, rarely absent. Stigmas peltate, crateriform, or bilaminar, rarely 2-lobed. 2n = 48, 72, 96.
Phenology: Flowering Jan–Apr.
Habitat: Sandy desert, dry washes.
Elevation: -50–1000 m.
Distribution
Ariz., Calif., Nev., Mexico (Baja California), Mexico (Sonora)
Discussion
Subspecies cooperi is most abundant in the Sonoran Desert. A single specimen collected recently in Santa Cruz County, Arizona (Carnahan 1365, ARIZ, MO) is anomalous in habitat (oak woodland), elevation (1525 m), flowering time (August), and apparent host (Artemisia). The specimen has pale flowers but otherwise keys closest to subsp. cooperi.
Selected References
None.