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.

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.

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not carunculate +
smooth +  and faintly rugose +
1.5mm +  and 1.8mm +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
acute;obtuse +
Barbara Ertter +
(S. Watson) S. L. Welsh & B. C. Johnston +
compound +  and simple +
10 cm100 mm <br />0.1 m <br /> (13 cm130 mm <br />0.13 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
2 cm20 mm <br />0.02 m <br /> (10 cm100 mm <br />0.1 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Potentilla dissecta var. decurrens +
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 />) +
coriaceous +
reduced +
free +  and distinct +
hairy +  and glabrous +
10 cm100 mm <br />0.1 m <br /> (13 cm130 mm <br />0.13 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
narrowly cuneate-oblanceolate +  and obovate +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Colo. +, Idaho +, Mont. +, Nev. +, Utah +  and Wyo. +
not +  and aggregated +
2400–3800 m +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
linear-lanceolate +  and narrowly elliptic +
1 cm10 mm <br />0.01 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 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 />) +
inconspicuous +  and obscured +
sparse;common;sparse +
Dry meadows, stony slopes, exposed ridges and summits, alpine and subalpine +
stoloniferous +  and short-rhizomatous +
straight +
sparse +  and dense +
less appressed +  and ascending +
crisped +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 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 /> (0.5 cm5 mm <br />0.005 m <br />) +
0.5mm;2.5mm +
turbinate +, patelliform +  and cupulate +
cymose +  and (1-)2-11(-20)-flowered +
crassinucellate +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
not +  and overlapping +
oblanceolate +  and obovate oblong cuneate flabellate or elliptic +
linear +  and oblanceolate +
palmate +  and pinnate +
inferior +  and superior +
clustered +, biseriate +  and superposed +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
free +  and distinct +
obcordate +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
3.5 cm35 mm <br />0.035 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
less separate +  and more or less overlapping +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
20 cm200 mm <br />0.2 m <br /> (32 cm320 mm <br />0.32 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
often not much longer +
Great Basin Naturalist +
not arillate +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
free +  and distinct +
not rooting +
reddish +  and green +
prostrate +  and ascending +
prostrate to decumbent +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
linear;ovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
deciduous +
distinct +
subapical +
papillate-swollen +  and filiform +
rough-thickened +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
not glaucous +
P. decurrens +, P. diversifolia var. decurrens +  and P. nelsoniana +
fleshy-thickened +
Potentilla ovina var. decurrens +
Potentilla ovina +
variety +
0.1 cm1 mm <br />0.001 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
2 (?) +  and 5 (?) +
ovate +  and oblong +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
inconspicuous +
enlarged +
0.7 cm7 mm <br />0.007 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
biennial +, annual +  and perennial +
plant +  and matted +