Potentilla gracilis var. elmeri

(Rydberg) Jepson

Fl. Calif. 2: 189. 1936.

Common names: Elmer’s or combleaf cinquefoil
EndemicIllustrated
Basionym: Potentilla elmeri Rydberg in N. L. Britton et al., N. Amer. Fl. 22: 315. 1908
Synonyms: P. bakeri Rydberg P. flabelliformis var. inyoensis Jepson P. pectinisecta Rydberg P. pectinisecta var. comosa (Rydberg) Soják
Treatment appears in FNA Volume 9. Treatment on page 156. Mentioned on page 154, 158.

Stems (1.5–)2–6(–8) dm. Basal leaves: petiole 2–15(–25) cm, long hairs common to dense, usually tightly appressed, sometimes ascending to spreading, 0.5–2.5 mm, stiff, crisped hairs absent or sparse, cottony hairs absent, glands absent or sparse; leaflets 5–7, usually ± overlapping, largest mostly oblanceolate to narrowly obovate, 2–6(–9) × 1.5–2.5 cm, margins flat to ± revolute, distal 3/4 to nearly whole length evenly incised 3/4+ to midvein, undivided medial blade 2–4 mm wide, teeth (5–)6–10 per side, not secondarily toothed, linear, 3–13(–20) mm, surfaces usually ± dissimilar, abaxial grayish to whitish, long hairs abundant to dense, crisped hairs sparse to abundant, cottony hairs usually absent, glands absent or sparse, adaxial green to grayish, long hairs ± abundant, rarely dense, crisped hairs absent or sparse, cottony hairs absent, glands absent or sparse. Flowers: epicalyx bractlets 2.5–5 × 0.5–1.2(–1.5) mm; hypanthium 3.5–5 mm diam.; petals 4–7(–8) × (3–)5–10 mm; carpels (20–)30–50, styles 1.5–3 mm. Achenes 1–1.3 mm. 2n = 42.


Phenology: Flowering summer.
Habitat: Vernally moist meadows, often semialkaline, dry gravelly flats and slopes, in sagebrush communities, aspen and conifer woodlands
Elevation: 1300–3300 m

Distribution

V9 227-distribution-map.jpg

Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wyo.

Discussion

Variety elmeri is the characteristic representative of Potentilla gracilis in the Great Basin, distinguished by deeply and evenly pectinate-toothed leaflets with a very narrow undivided medial blade. Leaflet surfaces are only somewhat dissimilar, most often grayish with abundant crisped (versus cottony) hairs abaxially. Basal leaves tend to be shorter than in other varieties, and petioles are most often tightly strigose. Intergradation with other varieties is common; populations beyond the Great Basin are problematic.

Selected References

None.

Lower Taxa

None.
Barbara Ertter +  and James L. Reveal +
(Rydberg) Jepson +
Potentilla elmeri +
Elmer’s or combleaf cinquefoil +
Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, Oreg. +, Utah +  and Wyo. +
1300–3300 m +
Vernally moist meadows, often semialkaline, dry gravelly flats and slopes, in sagebrush communities, aspen and conifer woodlands +
Flowering summer. +
Endemic +  and Illustrated +
P. bakeri +, P. flabelliformis var. inyoensis +, P. pectinisecta +  and P. pectinisecta var. comosa +
Potentilla gracilis var. elmeri +
Potentilla gracilis +
variety +