Potentilla nana
Potentilla wheeleri
arctic cinquefoil, dwarf cinquefoil
Kern cinquefoil, Wheeler's cinquefoil
ascending to erect, 0.1–0.5(–0.7) dm, lengths 1–2 times basal leaves.
0.2–2.5 dm.
not in ranks, ternate, 1–5 cm;
stipules: apex acute;
petiole 0.5–3.5 cm, long hairs sparse to abundant, ascending to spreading, 0.5–2 mm, ± soft, glands sparse to common;
leaflets 3, central obovate, 0.5–2 × 0.5–1 cm, petiolule 0–1 mm, margins revolute, not lobed, distal 1/2–2/3 evenly incised ± 1/2 to midvein, teeth 3–4(–6) per side, surfaces ± similar, green (paler abaxially), hairs sparse to abundant, 0.8–1.2 mm, glands sparse to common.
palmate, 1.5–9.5 cm;
petiole 1–7 cm, long hairs abundant to dense, spreading to appressed, 1–2 mm, weak to stiff, glands ± abundant;
leaflets 5, central cuneate-elliptic to obovate, 0.5–2.5 × 0.3–1.5 cm, scarcely to distinctly petiolulate, distal 1/3 of margins evenly incised ± 1/4 to midvein, teeth 2–4(–5) per side, surfaces gray-green, long hairs abundant to dense, 1–1.5 mm, glands ± abundant, sometimes obscured.
1(–2)-flowered.
1–20-flowered.
straight, 0.2–1.5 cm in flower, to 5 cm in fruit.
0.5–1.5 cm.
epicalyx bractlets oblong or ovate, 2.5–5 × 1.5–3.5 mm, margins revolute;
hypanthium 3–3.5 mm diam.;
sepals 2.5–5 mm, apex ± acute;
petals pale yellow, 4–8 × 4–6 mm;
filaments 1.2–2 mm, anthers 0.3–0.4 mm;
carpels 40–50, styles ± columnar, not or scarcely papillate-swollen proximally, 0.8–1.2 mm.
epicalyx bractlets lanceolate to ovate-elliptic, 1–3.5 × 1–1.5 mm;
hypanthium 2–4 mm diam.;
sepals 2–5 mm, apex ± acute;
petals ± paler abaxially, bright yellow adaxially, ± obcordate, 3–6 × 2–5 mm;
filaments 1–2 mm, anthers 0.5 mm;
carpels ca. 20, styles (1.2–)1.5–2 mm.
1.4–1.6 mm.
1–1.5 mm, lightly rugose.
hairs not well differentiated from long hairs, absent or sparse throughout.
Potentilla nana
Potentilla wheeleri
Potentilla nana has most often been considered a race of P. hyparctica or as the priority name for P. hyparctica. As now defined, P. nana occurs in an arc across southern Alaska, from the Aleutian and Pribilof islands to the Alaskan panhandle and adjacent British Columbia. T. Wolf (1908) treated it as a dwarf form of P. fragiformis; J. Soják (1996) interpreted P. nana as a hybrid species originating from cross(es) between P. fragiformis and P. hyparctica. Although the hybrid hypothesis has morphologic support, P. nana has a unique combination of morphologic features and has a distinct range from both P. fragiformis and P. hyparctica. The species are also ecologically segregated: P. nana is a coastal heath and gravel slope species, like P. hyparctica; P. fragiformis is strictly maritime coastal.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Potentilla wheeleri is found in the southern Sierra Nevada and San Bernardino Mountains of southern California. Compact plants on the summit of Mount San Gorgonio, described by Jepson as var. paupercula, show no consistent difference to justify their taxonomic segregation. Variety viscidula Rydberg has been misapplied to Arizona populations now called P. rhyolitica. Plants identified as P. wheeleri (excluding P. rimicola) from the Sierra San Pedro Mártir (Baja California) stand as a distinct species, P. luteosericea Rydberg (= P. pinetorum Wiggins).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
