Flora of North America species comparison

The name Potentilla glandulosa subsp. ashlandica was misapplied to Drymocallis lactea var. austiniae (B. Ertter 1993); as circumscribed here, D. ashlandica is a poorly known species restricted to the Cascade and Siskiyou ranges of southwestern Oregon. It very likely also occurs in adjacent California; no collections from there are known. Drymocallis ashlandica differs from most sympatric populations of D. lactea var. austiniae and resembles D. pseudorupestris in its densely glandular inflorescences, which tend to be more densely congested and/or narrower than those of the other two species.

Drymocallis ashlandica was described by Greene as Potentilla ashlandica, and by Howell as P. ciliata (a later homonym), both based on a collection by Howell from the Siskiyou Mountains near Ashland, Oregon. The circumscription here, which matches that of D. D. Keck (in J. Clausen et al. 1940) and M. E. Peck (1961), encompasses populations from near Oregon Caves and Ashland in the Siskiyou Mountains to near McKenzie Bridge, Lane County, and Sparks Lake, Deschutes County. It is currently known from relatively few collections, mostly from the Crater Lake area, and may prove to be of conservation concern.

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

Varieties 4 (4 in the flora).

Even with the removal of most of the subspecies of Potentilla glandulosa treated by Keck, Drymocallis glandulosa encompasses an inordinate range of variation. This is because of the apparently clinal variation between the coastal extreme (var. wrangelliana), with leafy inflorescences and broad cream-white petals, the montane var. reflexa, with less leafy inflorescences and narrow yellow petals, and the transitional interior var. glandulosa. Variety reflexa, in turn, intergrades in the mountains of southern California with var. viscida, which is anomalous in D. glandulosa with its narrow inflorescences and irregularly single-toothed leaflets. Variation outside of California is unclear, with no evident pattern to differences in petal size and color; these have largely been assigned to var. glandulosa.

At its most distinctive, Drymocallis glandulosa is a robust, densely glandular plant with widely branched leafy inflorescences (except var. viscida), relatively short, stout pedicels, broad sepals with rounded, mucronate tips (except var. viscida and sometimes var. reflexa) that are often significantly enlarged in fruit, and non-overlapping petals that are shorter than to scarcely equal to the sepals. The relatively large achenes are blunter and redder than those of most other species of Drymocallis, as discussed by J. Clausen et al. (1940).

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