Flora of North America species comparison

Pedicularis oederi is known from the mountains of Europe, Asia, and western North America.

Two arctic species can be easily confused with Pedicularis oederi. Pedicularis flammea also has bicolored flowers that are yellow with galeas that are red- or purple-tipped, but the flowers of P. oederi are twice the size of those of P. flammea. The flowers of P. capitata are sometimes also yellow but may or may not be bicolored. If bicolored, the color is more diffuse and lighter than that of either P. flammea or P. oederi. The flowers of P. capitata are also larger than those of P. oederi. In addition, the inflorescences of P. capitata usually have no more than five flowers clustered at the tips, while those of P. oederi have at least 10 to 50 flowers along at least one third their lengths. H. J. Scoggan (1978–1979) listed P. oederi var. albertae based upon its densely woolly inflorescence.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Subspecies 6 (5 in the flora).

Pedicularis sudetica is a difficult complex. Hultén employed the degree of lobing on subtending floral bracts, length of corolla tubes, and inflorescence vestiture in recognizing eight infraspecific taxa. U. Molau and D. F. Murray (1996) emphasized presence or absence of spots on the abaxial lip, inflorescence vestiture, length of petioles and calyx, and ecological features to define four species, subsuming several of Hultén’s other subspecific taxa into these species. According to Molau and Murray, P. sudetica in the narrow sense is a morphologically distinct, disjunct taxon endemic to the Sudeten Mountains of central Europe, but part of the broader circumscription by Hultén (1961, 1964), which is treated here as the sixth subspecies.

U. Molau and D. F. Murray (1996) did not include subsp. scopulorum in their analysis, noting only that teeth are virtually absent on the galea of Pedicularis scopulorum. Presence or absence of apical teeth on the margins of the galea often distinguishes species in other Pedicularis taxa. Because teeth are sometimes present in this taxon, it is treated here as one of the five North American subspecies in the broad sense of P. sudetica. A recent molecular study confirms its close relationship to other members of the complex (B. W. Robart et al. 2015).

When comparing the two alternative taxonomies, the treatment by U. Molau and D. F. Murray (1996) is easier to apply. Close inspection of specimens identified as these species often reveals combinations of traits attributable to more than one taxon; Molau and Murray reported finding hybridization common between Pedicularis albolabiata and P. arctoeuropaea, and P. albolabiata and P. pacifica where habitats overlap, indicating that reproductive isolation is not complete. Recognition of these taxa as varieties may be more appropriate considering the broad geographic overlap where the few distinguishing features tend to intergrade. They are treated here, however, as subspecies. The following key is modified from Molau and Murray.

(Discussion copyrighted by Flora of North America; reprinted with permission.)