Potentilla lasiodonta

Rydberg in N. L. Britton et al.

in N. L. Britton et al., N. Amer. Fl. 22: 351. 1908.

Common names: Sandhills cinquefoil
Endemic
Synonyms: Potentilla finitima Kohli & Packer
Treatment appears in FNA Volume 9. Treatment on page 214. Mentioned on page 212, 213, 215.

Stems ± erect, 2–4 dm. Basal leaves pinnate, 12–20 (–30) cm; petiole 5–10 (–15) cm, long hairs ± abundant, spreading to ascending, 0.5–1 mm, weak to ± stiff, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse to abundant, often obscured; leaflets 4–6 (–9) per side, on distal (1/3–) 1/2–3/5 of leaf axis, slightly overlapping, terminal ones oblanceolate to narrowly elliptic, 3–6 × 0.8–1.2 (–1.5) cm, margins strongly revolute, incised ± 1/2 to midvein, undivided medial blade 5–9 mm wide, teeth 8–12 per side, narrowly triangular to lanceolate, surfaces ± dissimilar, abaxial grayish, long hairs ± sparse (or not differentiated from short hairs), 0.5–1.5 mm, weak, short hairs abundant to dense, cottony or crisped hairs absent, glands sparse or obscured, adaxial ± green, straight hairs (long and short not differentiated) abundant, spreading to ascending, 0.2–0.5 mm, cottony and crisped hairs absent, glands sparse to abundant, often obscured. Cauline leaves (1–) 2–4. Inflorescences 10–40-flowered, congested or elongating in fruit. Pedicels ± 0.1 cm (proximal to 1.2 cm). Flowers: epicalyx bractlets narrowly ovate-acuminate, (3–) 4–8 (–10) × 2–3 mm, lengths 1–2 times sepals, margins ± revolute; hypanthium (4–) 5–10 mm diam.; sepals 3–5 mm, apex acute to obtuse, abaxial surfaces: venation moderate, glands ± abundant, obscured to evident; petals pale-yellow, 3–5 × 2–4 mm, lengths ± equal to or shorter than sepals; filaments 1–1.5 mm, anthers 0.5–0.8 mm; carpels 80–90, styles papillate-swollen in proximal 3/4+, 1–1.2 mm. Achenes ± 1 mm, ± rugose. 2n = 14.


Phenology: Flowering summer.
Habitat: Sandy sites in prairies
Elevation: 300–1100 m

Distribution

V9 322-distribution-map.jpg

Alta., Man., Sask., Minn., N.Dak.

Discussion

Potentilla lasiodonta is a diploid relative of tetraploid P. pensylvanica, sharing similar velvety vestiture of dense short hairs, pinnate leaves, and epicalyx bractlets with revolute margins. The species differs in having larger epicalyx bractlets and less deeply incised leaflets. Plant height and leaf size are at the upper range of P. pensylvanica, and populations are evidently restricted to sandy substrates. Occurrence in Manitoba is based on B. L. Kohli and J. G. Packer (1976); no vouchers are in WIN. At least one collection from southeastern British Columbia (Brown 779, MO) approaches P. lasiodonta, but it is insufficient by itself to serve as a provincial record.

The fundamental ploidy and epicalyx distinctions of this species were established by B. L. Kohli and J. G. Packer (1976), who proposed the name Potentilla finitima. As noted by J. Soják (1994), the type of P. lasiodonta is the same entity. Potentilla atrovirens Rydberg and P. pensylvanica var. arida B. Boivin have sometimes been applied to this taxon; the types of both names fall within the circumscription of P. pensylvanica in the narrow sense (Packer, pers. comm.).

Selected References

None.

Lower Taxa

None.

No values specified."dm" is not declared as a valid unit of measurement for this property.

... more about "Potentilla lasiodonta"
green +  and white +
green +  and grayish +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Barbara Ertter +  and Reidar Elven +
Rydberg in N. L. Britton et al. +
compound +  and simple +
opposite +  and alternate +
20 cm200 mm <br />0.2 m <br /> (30 cm300 mm <br />0.3 m <br />) +
12 cm120 mm <br />0.12 m <br /> (20 cm200 mm <br />0.2 m <br />) +
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 +
Sandhills cinquefoil +
Alta. +, Man. +, Sask. +, Minn. +  and N.Dak. +
not +  and aggregated +
300–1100 m +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
ovate-acuminate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 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 />) +
obscured +  and evident +
crisped +
Sandy sites in prairies +
stoloniferous +  and short-rhizomatous +
straight +
weak +  and more or less stiff +
spreading +  and ascending +
crisped +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
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 />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 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 />) +
crassinucellate +
bipinnate +, odd-pinnate +, subpalmate +, palmate +  and ternate +
opposite +  and alternate +
marcescent +
well-developed +
persistent +
cauline +  and basal +
reduced +
separate +  and overlapping +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (?) +  and 1.2 cm12 mm <br />0.012 m <br /> (?) +
linear +  and oblanceolate +
palmate +  and pinnate +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
inferior +  and superior +
clustered +, biseriate +  and superposed +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (?) +
0.5 cm5 mm <br />0.005 m <br /> (1.05 cm10.5 mm <br />0.0105 m <br />) +
free +  and distinct +
more or less equal to or shorter +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
10 cm100 mm <br />0.1 m <br /> (15 cm150 mm <br />0.15 m <br />) +
5 cm50 mm <br />0.05 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
pinnate +  and subpinnate or subpalmate +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (25 cm250 mm <br />0.25 m <br />) +
often significantly longer +
in N. L. Britton et al., N. Amer. Fl. +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
free +  and distinct +
not rooting +
reddish +  and green +
(1-)1.5-3(-4) times basal leaves +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
deciduous +
distinct +
subapical +
papillate-swollen +
rough-thickened +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Potentilla finitima +
not fleshy-thickened +
Potentilla lasiodonta +
Potentilla sect. Pensylvanicae +
species +
8 +  and 12 +
narrowly triangular +  and lanceolate +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +
herb +  and matted +