Flora of North America species comparison

Species 400–600 (37 in the flora).

E. Hultén (1968) listed three Pedicularis taxa in his Flora of Alaska and Neighboring Territories that do not occur in the flora area; P. amoena Adams ex Steven, P. kanei Durand subsp. adamsii (Hultén) Hultén, and P. villosa Ledebour ex Sprengel are found on the Chukchi Peninsula of Siberia.

The most common chromosome number for Pedicularis is 2n = 16. Two species are reported to have a diploid number of 2n = 12, and at least five species have a number of 2n = 14. See reviews in Jie C. et al. (2004) and M. I. S. Saggoo and D. K. Srivastava (2009).

Infrageneric classification of Pedicularis is both difficult and incomplete. The author has not attempted to present one for the North American taxa. Inconsistencies result from using either floral morphology or phyllotaxy to construct major subgeneric groups (C. Steven 1823; G. Bentham 1835; C. J. Maximowicz 1888; D. Prain 1890; G. Bonati 1918; Tsoong P. C. 1955); the latter author proposed 130 series to accommodate the worldwide variation in Pedicularis. Recognizing that floral form probably evolved in parallel among groups, Li H. L. (1948) employed phyllotaxy to erect three informal subgeneric taxa (greges) for the Pedicularis of China, including grex Allophyllum, species with alternate leaves; grex Cyclophyllum, species with opposite or verticillate arrangement of leaves; and grex Poecilophyllum, species with alternate to subopposite leaves on the same plant. However, molecular phylogenies (Yang F. S. et al. 2003; R. H. Ree 2005; B. W. Robart et al. 2015; Yu W. B. et al. 2015) indicate inconsistencies even in the treatment by Li, although the study by Yu et al., which included 257 species, did show that grex Cyclophyllum is monophyletic.

Pediculariopsis was described to account for species (for example, Pedicularis verticillata) that exhibit a different base chromosome number (x = 6 versus x = 8). That concept has not been accepted by others, because there is little morphological support.

The use of infraspecific ranks in Pedicularis follows T. F. Stuessy (1990), who argued that the subspecific rank is appropriate when several obvious morphological differences are associated with an allopatric or peripatric geographical pattern, whereas the varietal rank is appropriate when one to few differences are associated with more or less geographic overlap. Unfortunately, Pedicularis specialists have not used these levels consistently. The subspecies rank is used here, except in P. bracteosa, P. centranthera, and P. contorta.

Pedicularis is a common element of arctic and alpine habitats in the Northern Hemisphere, with the greatest concentration of species occurring in Asia.

(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.)