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

Hall's violet, Oregon violet, wild pansy

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

Habit Plants perennial, caulescent, not stoloniferous, 5–22 cm. Plants annual, caulescent, not stoloniferous, 5–35 cm.
Stems

1–3, decumbent or ascending to erect, ca. 1/2 subterranean, glabrous, clustered on single, short, vertical, deep-seated caudex.

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

Leaves

basal and cauline;

basal: 1–4, palmately compound, ± 2-ternate or 3-ternate, leaflets 3;

stipules adnate to petiole, forming 2 linear-lanceolate wings, unlobed, margins entire, apex of each wing free, acute;

petiole 5–8 cm, glabrous;

blade ovate to deltate, 2.8–6 × 2.6–6.5 cm, ± coriaceous, base tapered, ultimate lobes narrowly elliptic, lanceolate, or oblanceolate, 1–7 mm wide, margins entire, ciliate or eciliate, apex acute, mucronulate, surfaces glabrous;

cauline similar to basal except: stipules usually lanceolate, sometimes broadly ovate, ± leaflike, margins toothed;

petiole 1.3–6 cm;

blade 2–4.8 × 1.2–5.5 cm.

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.

Peduncles

2.5–11 cm, glabrous.

2–8 cm, glabrous or pubescent.

Flowers

sepals lanceolate to ovate, margins ciliate, auricles 0.5–1 mm;

petals: upper 2 almost black abaxially, dark reddish violet adaxially, lower 3 pale yellow, cream, or ± white, lateral 2 bearded, with deep yellow to orange patch basally, dark reddish violet-veined, lowest with deep yellow to orange patch basally, dark reddish violet-veined, 5–18 mm, spur yellow, gibbous, 0.5–2 mm;

style head bearded; cleistogamous flowers absent.

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.

Capsules

ellipsoid, 4–12 mm, glabrous.

± spherical, 5–9 mm, glabrous.

Seeds

light brown, shiny, 3.2–3.5 mm.

brown, 1.5–1.9 mm.

2n

= 60, 72.

= 34.

Viola hallii

Viola arvensis

Phenology Flowering Apr–Jul. Flowering May–Jul.
Habitat Open forests, grassy hills, chaparral, frequently serpentine or gravelly soil Abandoned fields, roadsides, lawns
Elevation 500–2100 m (1600–6900 ft) 0–3000 m (0–9800 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
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]
Discussion

Viola hallii was discovered on the grounds of Willamette University in Salem, Oregon, by Elihu Hall, a professor at that institution (V. B. Baird 1942). Leaves of V. hallii are similar to V. beckwithii.

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

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.)

Source FNA vol. 6, p. 133. FNA vol. 6, p. 121.
Parent taxa Violaceae > Viola Violaceae > Viola
Sibling taxa
V. adunca, 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. 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. 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
Synonyms Mnemion arvense, V. tricolor var. arvensis
Name authority A. Gray: Proc. Amer. Acad. Arts 8: 377. (1872) Murray: Prodr. Stirp. Gott., 73. (1770)
Web links