Flora of North America species comparison

The application of the epithet pseudocapitata here differs significantly from that of P. A. Rydberg (1908c), D. D. Keck (1938), and most floras, who used it for the taxon that is here called var. brownii. Instead, var. pseudocapitata encompasses the bulk of what had been called var. (or subsp.) capitata, except in mountains bordering the Palouse Prairie in Idaho, Oregon, and Washington. For nomenclatural details, see B. Ertter and J. L Reveal (2007).

As here circumscribed, var. pseudocapitata is a relatively large, big-petaled variety that grows in the mountains in and bordering the northern Intermountain Region in northeastern California (primarily the Warner Mountains), northern Nevada, southeastern Oregon, and southern Idaho, extending northward along valleys from Camas to Blaine counties. Intermediate plants are common where the range intersects those of var. brownii, var. capitata, and var. parviflora, though in the core of its range var. pseudocapitata is reasonably distinctive and uniform.

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

Variety parviflora is the most widespread and polymorphic in the species and might represent the repository for variation that is not accommodated by the other, more tightly circumscribed varieties. Population clusters occur in three discrete areas: the Sierra Nevada of eastern California and adjacent Nevada, the mountains of northern California extending north in the Cascade Range to central Oregon, and the mountains of central Idaho. Each of these three areas has plants that differ slightly from those of the other two.

The most distinct phase is found in the Cascade Range of Oregon, with larger-than-average petals and highly branched inflorescences. Plants from Lost Prairie in eastern Linn County are particularly anomalous, with petals to 6.5 mm; further studies may indicate that these deserve separate recognition.

Plants from the Sierra Nevada tend to have smaller petals, and those in the higher southern Sierra Nevada tend to have capitate or subcapitate inflorescences. From about Lake Tahoe northward, inflorescences tend to be somewhat more open but still congested compared to the Oregon phase.

The Idaho phase, represented by the type of var. parviflora, has petals that run the full range from 2–4 mm, with most individuals having a slightly branched inflorescence. Unlike those of the other two phases, both the hypanthia and sepals are often purple; the hypanthium is otherwise typically greenish with only the sepals themselves a dark purple. The sole Wyoming record (D. R. Goddard 1027, F, UC) has yet to be confirmed by more recent collections in Yellowstone National Park. These plants have pale inflorescences, relatively blunt sepals, and short epicalyx bractlets, differing in these features from the closest populations in central Idaho. For reports from Montana, see species discussion.

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