Flora of North America species comparison

Primula incana is usually heavily farinose, at least when young, and has relatively tall scapes and tight umbels of homostylous flowers. As with some species of the genus, anthesis often begins before the scape is fully elongated; plants at first are quite small, but elongate throughout anthesis and typically become relatively tall and lanky in age. This has led to confusion with other arctic species, especially P. stricta, which has considerably less farina, a shorter scape, and a more maritime distribution. In fruiting stage, P. incana has been confused with P. laurentiana, which has looser umbels throughout anthesis, larger flowers, and a more eastern distribution. Primula incana generally replaces P. laurentiana to the west and south of Hudson Bay. The single octoploid count for P. incana is questionable; the species appears to be consistently hexaploid in other counts.

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

Subspecies 2 (2 in the flora).

Heterostylous representatives of Primula cuneifolia occur primarily in Asia, where this form predominates and the homostylous taxon is quite rare. It is not known whether the Asian homostyles are directly related to the North American complex, or, alternatively, represent separate mutations to homostyly from the Asian heterostylous stock; additional genetic studies are needed to assess these relationships. In North America, the heterostylous subsp. cuneifolia has been found only in the western Aleutian Islands. The homostylous subsp. saxifragifolia is found throughout most of Alaska and south to Vancouver Island. The subspecies differ somewhat in their vegetative morphology. Subspecies saxifragifolia typically has shorter scapes and petioles and fewer flowers than subsp. cuneifolia; these characters overlap and may correlate at least in part to environmental factors.

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