Orobanche corymbosa subsp. mutabilis
Canad. J. Bot. 56: 187. 1978.
Plants simple, rarely branched. Inflorescences short racemes or racemelike to elongate corymbs. Calyces 12–18 mm, sometimes equal to or longer than corolla. Corollas rose, pink, pale-purple, or white with darker veins, glabrate or slightly glandular-pubescent; anthers tomentose or glabrous.
Phenology: Flowering Jun–Sep.
Habitat: Sandy soils and rocky slopes in open sagebrush communities.
Elevation: 300–3200 m.
Alta., B.C., Man., Calif., Nev., N.Mex., Wyo.
Populations of subsp. mutabilis are more abundant in the northern portion of the range; populations elsewhere appear to be somewhat isolated. The more elongated inflorescence seems to be the distinguishing character, although this is often difficult to determine. The corollas often display less pigmentation. Anthers vary from quite woolly in some populations to completely glabrous in other populations. This variation could be the result of geographic isolation or hybridization.