The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

European field violet, European field-pansy, field pansy, field violet, pansy, violette des champs, wild pansy

Cascades early blue violet, common periwinkle, early blue violet, hook-spur violet, hookedspur violet, large periwinkle, sand violet, western dog violet, wild dog violet

Habit Plants annual, caulescent, not stoloniferous, 5–35 cm. Plants perennial, caulescent, not stoloniferous, 1.8–30(–35) cm.
Stems

1–5, usually erect, sometimes prostrate or decumbent, branched, subglabrous or puberulent, clustered on taproot.

1–5, erect, ascending, or decumbent, sometimes later reclining to nearly prostrate, glabrous or puberulent, on caudex from subligneous rhizome.

Leaves

cauline;

stipules palmately lobed, middle lobe oblanceolate, obovate, elliptic, or lanceolate, ± equaling leaf blade, proximal lobes dissected, shorter, margins ciliate, apex acute to obtuse;

petiole 0.5–2.3 cm, glabrous or puberulent;

blade: proximal ovate to ± oblong, distal narrowly or broadly lanceolate, 0.8–3.4 × 0.3–1.9 cm, base attenuate to ± truncate, margins coarsely crenate-serrate, ciliate or eciliate, apex acute to obtuse, surfaces pubescent abaxially, at least on major veins, glabrous adaxially.

basal and cauline;

basal: 1–4;

stipules linear to linear-lanceolate, margins entire or laciniate with gland-tipped projections, apex acute to acuminate;

petiole 0.5–13.5 cm, glabrous or puberulent;

blade usually ovate or ovate-deltate to ovate-orbiculate, sometimes ± reniform or oblong, 0.5–6.9 × 0.4–5 cm, base cordate, subcordate, truncate, or attenuate, usually decurrent on petiole, margins crenate to crenulate or entire, ciliate or eciliate, apex acute to obtuse, surfaces glabrous or sparsely to densely puberulent;

cauline similar to basal except: stipule margins lacerate to laciniate;

petiole 0.5–6.5 cm;

blade 0.6–5.5 × 0.4–4.7 cm.

Peduncles

2–8 cm, glabrous or pubescent.

1.7–13.8 cm, glabrous or puberulent.

Flowers

sepals lanceolate, margins ciliate or eciliate, auricles 2–4 mm;

petals white to pale yellow on both surfaces, upper 2 ± violet, lower 3 with yellow basal area, often violet-veined, lateral 2 bearded, ± equaling or shorter than sepals, lowest with dark yellow area basally, 7–15 mm, spur blue-violet to purple, elongated, 3–5 mm;

style head bearded; cleistogamous flowers absent.

sepals lanceolate, margins ciliate or eciliate, auricles not enlarged in fruit, 0.5–2 mm;

petals light- to deep- to lavender-violet on both surfaces, rarely white, lower 3 usually white basally, dark violet-veined, lateral 2 (and sometimes upper 2) bearded, lowest 7–17(–23) mm, spur purple to violet or white, elongated, 5–7 mm, tip straight or pointed, curved up or lateral;

style head sparsely to densely bearded, sometimes beardless; cleistogamous flowers axillary.

Capsules

± spherical, 5–9 mm, glabrous.

short-ovoid, 6–11 mm, glabrous.

Seeds

brown, 1.5–1.9 mm.

dark brown to olive-black, 1.5–2 mm.

2n

= 34.

Viola arvensis

Viola adunca

Phenology Flowering May–Jul.
Habitat Abandoned fields, roadsides, lawns
Elevation 0–3000 m (0–9800 ft)
Distribution
from FNA
CA; CT; DC; DE; GA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NY; OH; OR; PA; RI; SC; TN; UT; VA; VT; WA; WI; WV; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; SPM; Asia (Siberia); Greenland; Europe; Africa [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AZ; CA; CO; IA; ID; MA; ME; MI; MN; MT; ND; NE; NH; NM; NV; NY; OR; SD; UT; VT; WA; WI; WY; AB; BC; MB; NB; NS; NT; NU; ON; QC; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

A. R. Clapham et al. (1987) noted that Viola arvensis is pollinated by insects and is often selfed; T. Marcussen and T. Karlsson (2010) stated that V. arvensis regularly self-pollinates. Roots of V. arvensis have the odor of wintergreen when crushed (A. E. Radford et al. 1968; W. J. Hayden and J. Clough 1990). Viola arvensis is not vegetatively distinguishable from V. tricolor var. tricolor.

G. Halliday (pers. comm.) reported that Viola arvensis occurs in southwestern Greenland, where it is introduced, and is ephemeral on St. Pierre and Miquelon.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 2 (2 in the flora).

Viola adunca is polymorphic with over 50 named taxa. G. D. McPherson and J. G. Packer (1974) reported that diploid, triploid, and tetraploid races of V. adunca occur in Canada and northwestern United States. They found that diploid and tetraploid chromosome races can be distinguished morphologically based on style beards and on the size of guard cells and pollen grains and recommended taxonomic recognition of both races. In diploid races, the style projections are more or less cylindrical and about one-sixth the width of the style; in tetraploid races they are short-conical or globular, and about one-tenth or less than the width of the style beard.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Plants (4–)4.5–30(–35) cm; basal blades 1.3–6.9 × 1.2–5 cm; peduncles 3–13.8 cm; 0–3600 m; widespread in North America.
var. adunca
1. Plants 1.8–4.5(–6.5) cm; basal blades 0.5–1.7 × 0.4–1.4 cm; peduncles 1.7–5 cm; 2500–3800 m; restricted to Rocky Mountains (Colorado, Montana, Wyoming, British Columbia).
var. bellidifolia
Source FNA vol. 6, p. 121. FNA vol. 6, p. 119.
Parent taxa Violaceae > Viola Violaceae > Viola
Sibling taxa
V. adunca, V. affinis, V. bakeri, V. beckwithii, V. bicolor, V. biflora, V. blanda, V. brittoniana, V. canadensis, V. canina, V. charlestonensis, V. clauseniana, V. cucullata, V. cuneata, V. douglasii, V. egglestonii, V. epipsila, V. flettii, V. frank-smithii, V. glabella, V. guadalupensis, V. hallii, V. hastata, V. hirsutula, V. howellii, V. japonica, V. labradorica, V. lanceolata, V. langsdorffii, V. lithion, V. lobata, V. macloskeyi, V. missouriensis, V. nephrophylla, V. novae-angliae, V. nuttallii, V. ocellata, V. odorata, V. orbiculata, V. palmata, V. palustris, V. pedata, V. pedatifida, V. pedunculata, V. pinetorum, V. praemorsa, V. primulifolia, V. prionantha, V. pubescens, V. purpurea, V. quercetorum, V. renifolia, V. riviniana, V. rostrata, V. rotundifolia, V. sagittata, V. selkirkii, V. sempervirens, V. septemloba, V. sheltonii, V. sororia, V. striata, V. subsinuata, V. tomentosa, V. tricolor, V. trinervata, V. tripartita, V. umbraticola, V. utahensis, V. vallicola, V. villosa, V. walteri
V. affinis, V. arvensis, V. bakeri, V. beckwithii, V. bicolor, V. biflora, V. blanda, V. brittoniana, V. canadensis, V. canina, V. charlestonensis, V. clauseniana, V. cucullata, V. cuneata, V. douglasii, V. egglestonii, V. epipsila, V. flettii, V. frank-smithii, V. glabella, V. guadalupensis, V. hallii, V. hastata, V. hirsutula, V. howellii, V. japonica, V. labradorica, V. lanceolata, V. langsdorffii, V. lithion, V. lobata, V. macloskeyi, V. missouriensis, V. nephrophylla, V. novae-angliae, V. nuttallii, V. ocellata, V. odorata, V. orbiculata, V. palmata, V. palustris, V. pedata, V. pedatifida, V. pedunculata, V. pinetorum, V. praemorsa, V. primulifolia, V. prionantha, V. pubescens, V. purpurea, V. quercetorum, V. renifolia, V. riviniana, V. rostrata, V. rotundifolia, V. sagittata, V. selkirkii, V. sempervirens, V. septemloba, V. sheltonii, V. sororia, V. striata, V. subsinuata, V. tomentosa, V. tricolor, V. trinervata, V. tripartita, V. umbraticola, V. utahensis, V. vallicola, V. villosa, V. walteri
Subordinate taxa
V. adunca var. adunca, V. adunca var. bellidifolia
Synonyms Mnemion arvense, V. tricolor var. arvensis Lophion aduncum, V. canina var. adunca
Name authority Murray: Prodr. Stirp. Gott., 73. (1770) Smith: in A. Rees, Cycl. 37: Viola no. 63
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