Orobanche cooperi subsp. palmeri
Phytoneuron 2015-48: 16. 2015.
Plants sometimes branched, base sometimes enlarged. Leaves imbricate proximally; blade narrowly lanceolate to broadly ovate, 6–10 mm, apex acute. Inflorescences: bracts 7–12 mm, apex acute to acuminate, strongly reflexed. Corollas 15–18(–22) mm; palatal folds densely villous distally; abaxial lip 3–5 mm, adaxial lip reflexed or revolute, 4–6 mm, lobes with or without apiculate tooth, sometimes truncate. Anthers glabrous or tomentulose along sutures, stalked glands often few on dorsal surface or absent. Stigmas bilaminar-rhomboid, peltate, or crateriform, rarely 2-lobed. 2n = 48.
Phenology: Flowering Aug–May.
Habitat: Volcanic mountains, sand dunes, dry washes, hillsides.
Elevation: 100–1800 m.
Distribution
N.Mex., Tex., Mexico (Chihuahua, Coahuila, Durango, Hidalgo, San Luis Potosí).
Discussion
Subspecies palmeri is found principally in the Chihuahuan Desert from southern New Mexico and western Texas southward to central Mexico. The known hosts are a few species of Viguiera (Asteraceae).
Subspecies palmeri is sometimes confused with the Mexican species, Orobanche dugesii (S. Watson) Munz. An issue regarding the separation of subsp. palmeri from O. dugesii, raised by G. C. de Rzedowski (1998), was addressed by L. T. Collins and G. Yatskievych (2015), who maintained the two taxa as separate entities.
Selected References
None.