Potentilla ovina var. decurrens

(S. Watson) S. L. Welsh & B. C. Johnston

Great Basin Naturalist 42: 30. 1982.

Endemic
Basionym: Potentilla dissecta var. decurrens S. Watson Proc. Amer. Acad. Arts 8: 557. 1873
Synonyms: P. decurrens (S. Watson) Rydberg P. diversifolia var. decurrens (S. Watson) Th. Wolf P. nelsoniana Rydberg
Treatment appears in FNA Volume 9. Treatment on page 172. Mentioned on page 153, 170, 171.
Revision as of 22:39, 16 December 2019 by FNA>Volume Importer

Stems: lengths (1.5–)2–3 times basal leaves. Basal leaves 2–10(–13) × 1–3.5(–5) cm; petiole 0.5–3.5(–5) cm; lateral leaflets on distal 1/2–2/3(–3/4) of leaf axis, ± separate, distal leaflets narrowly cuneate-oblanceolate to obovate, (0.5–)1–2(–3.5) cm, distal 1/4–1/2(–3/4) of margin unevenly to pinnately incised 1/2–2/3(–3/4) to midvein, teeth 2–5(–7), ovate to oblong, 1–7 × 1–2 mm, surfaces green, hairs absent (except on margins) or sparse, 0.5–1 mm. Achenes 1.5–1.8 mm.


Phenology: Flowering summer.
Habitat: Dry meadows, stony slopes, exposed ridges and summits, alpine and subalpine
Elevation: 2400–3800 m

Distribution

V9 250-distribution-map.jpg

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

Discussion

Variety decurrens at its most distinctive has elongate cuneate-oblanceolate, glabrate, apically toothed leaflets that are well spaced on the leaf axis. This extreme is most commonly found in the Uinta Mountains of Utah and the Medicine Bow Mountains of Wyoming. Collections from Colorado, Idaho, Montana, and Nevada are more equivocal and might represent hybrids or extreme forms of other (or undescribed) taxa.

Although B. C. Johnston (1980) is provisionally followed in associating var. decurrens with Potentilla ovina, comparisons can also be made with P. drummondii and P. glaucophylla, both placed here in sect. Graciles. Apparent intergradation exists in all directions.

Selected References

None.

Lower Taxa

None.
Barbara Ertter +
(S. Watson) S. L. Welsh & B. C. Johnston +
Potentilla dissecta var. decurrens +
Colo. +, Idaho +, Mont. +, Nev. +, Utah +  and Wyo. +
2400–3800 m +
Dry meadows, stony slopes, exposed ridges and summits, alpine and subalpine +
Flowering summer. +
Great Basin Naturalist +
P. decurrens +, P. diversifolia var. decurrens +  and P. nelsoniana +
Potentilla ovina var. decurrens +
Potentilla ovina +
variety +