9. Drymocallis pseudorupestris (Rydberg) Rydberg, Monogr. N. Amer. Potentilleae. 194. 1898.
Potentilla pseudorupestris Rydberg, Bull. Torrey Bot. Club 24: 250, plate 307. 1897; Drymocallis glandulosa (Lindley) Rydberg subsp. pseudorupestris (Rydberg) Soják; P. glandulosa Lindley subsp. pseudorupestris (Rydberg) D. D. Keck; P. glandulosa var. pseudorupestris (Rydberg) Breitung; P. rupestris Linnaeus var. americana Th. Wolf
Caudex branches elongate. Stems openly tufted to loosely spaced, (0.3–)0.6–4 dm; base 1–3 mm diam., ± densely septate-glandular. Leaves glabrate or sparsely to ± densely hairy; basal (2–)3–16 cm, leaflet pairs (2–)3–4(–5); terminal leaflet broadly obovate-cuneate to flabellate, 0.2–3(–4) × 0.5–3 cm, teeth single or double, 2–15 per side, apex usually rounded to truncate, sometimes obtuse; cauline 0–2, reduced, leaflet pairs 2–3. Inflorescences 2–40-flowered, not or ± leafy, open, 1/6–3/4(–4/5) of stem, ± wide, branch angles (10–)20–40(–50)°. Pedicels 3–20 (proximal to 40) mm, not or sparsely to moderately short-hairy, predominantly septate-glandular. Flowers opening widely; epicalyx bractlets linear to elliptic, 2–6 × 1–2 mm; sepals spreading, 4–7(–9) mm, apex acute to obtuse, apiculate; petals overlapping or not, spreading, cream-white to pale yellow (red-tinged in var. crumiana), narrowly to broadly obovate, 4–12 × 3–11 mm, longer than sepals; filaments 1–4 mm, anthers 0.7–1.2 mm; styles thickened, 1–1.5 mm. Achenes light brown, 1 mm.
Varieties 3 (3 in the flora): w North America.
Drymocallis pseudorupestris occurs from Alberta and Washington to California and Utah, mostly in montane habitats; it is the species most often associated with rocky habitats, including talus slopes, for which its relatively elongate caudex branches are an obvious adaptation. Vestiture is dominated by abundant septate glands on stems and in the inflorescences. Except for var. pseudorupestris, which occurs only in the northeastern part of the species range, plants are relatively short, usually less than 2.5 dm. Three intergrading varieties accommodate the extremes at the northeastern and southern ends of the range.