Potentilla tikhomirovii

Jurtzev in A. I. Tolmatchew

in A. I. Tolmatchew, Fl. Arct. URSS 9(1): 318. 1984.

Treatment appears in FNA Volume 9. Treatment on page 201. Mentioned on page 196, 197.

Plants ± tufted. Caudex branches slender to stout, not columnar, not sheathed with marcescent whole leaves. Stems ± ascending, sometimes nearly erect, 0.5–1.5 (–3) dm, lengths 2–4 times basal leaves. Basal leaves 2–4 cm; petiole 1–2.5 cm, long hairs common to abundant, spreading to ascending, rarely loosely appressed, 1–2 mm, ± stiff, verrucose, short-crisped hairs sparse to abundant, sometimes nearly absent, cottony hairs absent, glands sparse; leaflets ± overlapping, central elliptic to obovate, 1–1.5 × 0.6–1.1 cm, petiolulate, base broadly cuneate, margins flat or slightly revolute, distal ± 2/3 incised ± 1/2 to midvein, teeth (3–) 4 per side, ± approximate, surfaces ± dissimilar, abaxial reddish or greenish gray to white, long hairs 1 mm, cottony-crisped hairs common to dense, adaxial green or reddish to gray-green, long hairs sparse to abundant, short-crisped hairs absent or sparse to common. Cauline leaves 0–1. Inflorescences 2–5-flowered. Pedicels 1–2 cm in flower, to 3 (–5) cm in fruit. Flowers: epicalyx bractlets narrowly elliptic to narrowly ovate, 4–6 × 1–2.5 mm, (1/2–) 2/3 to as wide as sepals, margins revolute, sometimes flat, red-glands usually common, conspicuous; hypanthium 3.5–4.5 mm diam.; sepals 5–7 mm, apex subacute; petals 6–8 × (4–) 5–8 mm, longer than sepals; filaments 0.7–1.2 mm, anthers 0.4 mm; carpels 40–60, apical hairs absent, styles columnar, strongly papillate-swollen in proximal 1/5–1/3, 0.9–1 mm. Achenes 1.2–1.8 mm. 2n = 42, 49 (Russian Far East).


Phenology: Flowering summer.
Habitat: Dry tundra meadows, loamy soil banks, sedge-herb slopes
Elevation: 0–1100 m

Distribution

Greenland, N.W.T., Nunavut, Alaska, Europe (Russia), Asia

Discussion

Potentilla tikhomirovii is an assumed hybrid species combining characteristics from P. arenosa subsp. arenosa of sect. Niveae (abaxial leaflet surfaces with crisped-cottony hairs, adaxial surfaces with both long and short hairs, petioles often with both long and short hairs, and flower shape and size) and P. hyparctica of sect. Aureae (crisped-cottony hairs often not fully covering abaxial leaf surfaces, reddish color in most plant parts, sepals and epicalyx bractlets relatively large, broad, less acute, and with many and reddish glands, which are often also on petioles and stipules).

Potentilla tikhomirovii has an interrupted range and is not very coherent morphologically. It forms large populations locally, probably by agamic seed propagation, and is a significant part of the Potentilla variation in northern and northeastern Greenland, Ellesmere Island, and parts of the Brooks Range, northern Alaska. Both the distributional and the morphologic patterns indicate that it has evolved multiple times in different regions, such that it is a borderline case for status as an independent species. Its large populations and significant distribution in some regions support recognition, as also does the paucity of obvious back-crosses with the parents.

Selected References

None.

Lower Taxa

None.

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

... more about "Potentilla tikhomirovii"
reddish +, yellowish white +, gray +  and white +
cottony-crisped +
reddish +, yellowish white +, gray +  and white +
cottony-crisped +
greenish gray +  and white +
cottony-crisped +
rugose +  and smooth +
1.2mm +  and 1.8mm +
reddish +  and gray-green +
0.4 cm4 mm <br />0.004 m <br /> (?) +
Reidar Elven +, David F. Murray +  and Barbara Ertter +
Jurtzev in A. I. Tolmatchew +
compound +  and simple +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
cuneate +
Niveae +
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 +
slender +  and stout +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
elliptic +  and obovate +
0.6 cm6 mm <br />0.006 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
Greenland +, N.W.T. +, Nunavut +, Alaska +, Europe (Russia) +  and Asia +
not +  and aggregated +
0–1100 m +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
narrowly elliptic +  and narrowly ovate +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 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 />) +
crisped +
Dry tundra meadows, loamy soil banks, sedge-herb slopes +
stoloniferous +  and short-rhizomatous +
straight +
spreading +  and ascending +
sparse +  and common +
verrucose +
short-crisped +  and cottony-crisped +
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 /> (0.5 cm5 mm <br />0.005 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 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 +
obtriangular +, suborbiculate +, elliptic +  and obovate +
linear +  and oblanceolate +
palmate +  and pinnate +
1/2 +  and 2/3 +
incised +, revolute +  and flat +
inferior +  and superior +
clustered +, biseriate +  and superposed +
3 cm30 mm <br />0.03 m <br /> (5 cm50 mm <br />0.05 m <br />) +
0 cm0 mm <br />0 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
free +  and distinct +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
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 /> (0.8 cm8 mm <br />0.008 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Flowering summer. +
adnate +, free +, connate +  and distinct +
palmate +  and ternate +
12 cm120 mm <br />0.12 m <br /> (20 cm200 mm <br />0.2 m <br />) +
1 cm10 mm <br />0.01 m <br /> (12 cm120 mm <br />0.12 m <br />) +
in A. I. Tolmatchew, Fl. Arct. URSS +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
free +  and distinct +
not rooting +
reddish +  and green +
2-4 times basal leaves +
erect +  and ascending +
1 +  and many +
not flagelliform +
palmate +  and pinnate +
linear;ovate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
deciduous +
distinct +
proximal +  and subapical +
papillate-swollen +  and columnar +
rough-thickened +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
not fleshy-thickened +
Potentilla tikhomirovii +
Potentilla sect. Niveae +
species +
inconspicuous +
enlarged +
biennial +, annual +  and perennial +