Potentilla ambigens

Greene

Erythea 1: 5. 1893.

Common names: Silkyleaf or giant or southern Rocky Mountain cinquefoil
Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 164. Mentioned on page 162.

Stems (2–) 3–7 (–8) dm, lengths (1–) 1.5–2.5 times basal leaves. Basal leaves pinnate, 15–45 (–50) cm; petiole (5–) 8–20 cm, long hairs abundant to dense, ascending to appressed, (1–) 2–3 mm, ± stiff, rarely weak, short or crisped hairs absent or sparse, cottony hairs absent, glands sparse, often obscured; leaflets not conduplicate, lateral ones evenly paired, (3–) 4–7 per side on distal ± 1/2 of leaf axis, most pairs ± decurrent, rachis winged, distal sometimes confluent with terminal leaflet, larger leaflets narrowly obovate, (2–) 3–7 × 1–2.5 cm, distal 3/4+ of margin incised 1/3 to midvein, teeth 6–18 per side, 1–4 mm, surfaces ± similar, abaxial grayish, long hairs sparse to common (mostly on veins), 0.5–2 mm, ± stiff, rarely weak, short-crisped hairs absent or sparse to common, cottony hairs absent, glands sparse to common, adaxial green to grayish, long and short hairs not differentiated, sparse to common, crisped and cottony hairs absent, glands absent or sparse. Cauline leaves (0–) 1–3. Inflorescences (10–) 20–60-flowered. Pedicels (0.5–) 1–3 (–6) cm. Flowers: epicalyx bractlets lanceolate to narrowly ovate or elliptic, 3–6 × 1–1.5 mm, 2/3 as long as to nearly equal to sepals, abaxial vestiture ± similar to sepals, not glabrescent, straight hairs sparse to common, crisped or cottony hairs usually absent; hypanthium 3–6 mm diam.; sepals 4–7 mm, apex acute to acuminate; petals (6–) 7–10 × 5–9 mm; filaments (1–) 1.5–4 mm, anthers 0.7–0.9 (–1) mm; carpels 20–30, styles (1–) 1.8–3 mm. Achenes 1.4–1.6 mm, smooth. 2n = 82.


Phenology: Flowering summer.
Habitat: Dry meadows and adjacent slopes, in conifer woodlands
Elevation: 2000–2700 m

Discussion

Of conservation concern.

Potentilla ambigens is one of the more distinctive species in sect. Leucophyllae, comprising exceptionally large plants with large, coarsely hairy leaves. Although sometimes confused with P. hippiana, P. ambigens lacks the crisped-cottony vestiture of that species and is usually morphologically distinctive even where both species occur together (D. G. Anderson, www.fs.fed.us/r2/projects/scp/assessments/potentillaambigens.pdf).

Potentilla ambigens occurs in Wyoming (at least historically), along the eastern slope of the Rocky Mountains to northern Colorado, and in scattered locations in the high mountains of New Mexico as far south as the Sacramento Mountains, Otero County. The species is of conservation concern in Colorado and has not been documented in Wyoming since 1900 (D. G. Anderson, www.fs.fed.us/r2/projects/scp/assessments/potentillaambigens.pdf).

Selected References

None.

Lower Taxa

None.

"dm" is not declared as a valid unit of measurement for this property.

... more about "Potentilla ambigens"
smooth +  and slightly rugose +
1.4mm +  and 1.6mm +
green +  and grayish +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
Barbara Ertter +  and James L. Reveal +
Greene +
compound +  and simple +
45 cm450 mm <br />0.45 m <br /> (50 cm500 mm <br />0.5 m <br />) +
15 cm150 mm <br />0.15 m <br /> (45 cm450 mm <br />0.45 m <br />) +
Leucophyllae +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
less cordate or reniform +  and narrowly elliptic +
0.5 cm5 mm <br />0.005 m <br /> (25 cm250 mm <br />0.25 m <br />) +
reduced +
free +  and distinct +
hairy +  and glabrous +
Silkyleaf or giant or southern Rocky Mountain cinquefoil +
Colo. +, N.Mex. +  and Wyo. +
not +  and aggregated +
2000–2700 m +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
lanceolate +  and narrowly ovate or elliptic +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
on style scar +, hairy +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
weak +  and stiff +
Dry meadows and adjacent slopes, in conifer woodlands +
stoloniferous +  and short-rhizomatous +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
straight +
weak +  and stiff +
ascending +  and appressed +
sparse +  and common +
crisped +  and short-crisped +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
not differentiated +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
(10-)20-60-flowered +
crassinucellate +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
decurrent +
linear +  and oblanceolate +
palmate +  and pinnate +
less +, 1/4 +  and 1/2 +
inferior +  and superior +
clustered +, biseriate +  and superposed +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
free +  and distinct +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
usually longer +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
5 cm50 mm <br />0.05 m <br /> (8 cm80 mm <br />0.08 m <br />) +
8 cm80 mm <br />0.08 m <br /> (20 cm200 mm <br />0.2 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
pinnate +  and subpinnate +
45 cm450 mm <br />0.45 m <br /> (50 cm500 mm <br />0.5 m <br />) +
3 cm30 mm <br />0.03 m <br /> (45 cm450 mm <br />0.45 m <br />) +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
not rooting +
reddish +  and green +
(1-)1.5-2.5 times basal leaves +
ascending +  and erect +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
0.1 cm1 mm <br />0.001 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
deciduous +
distinct +
subapical +
papillate-swollen +  and tapered-filiform +
rough-thickened +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Hippianae +  and Potentilla sect. Hippianae +
not fleshy-thickened +
Potentilla ambigens +
Potentilla sect. Leucophyllae +
species +
6 +  and 18 +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
herb +  and matted +