Viola sororia
Viola biflora
common blue violet, common or downy or woolly blue violet, northern blue violet, northern violet, northern woodland violet, violette parente, woolly blue violet
arctic yellow violet, European field pansy, northern violet, queen Charlotte twinflower violet, twinflower violet
1–3+, ascending or erect, leafy proximally and distally, glabrous, on caudex from fleshy rhizome.
basal, 1–8, ascending to erect;
stipules linear-lanceolate to broadly lanceolate, margins entire, sometimes glandular distally, apex acute;
petiole 2–25 cm, pubescent or glabrous;
blade green abaxially, unlobed, ovate or broadly ovate to reniform, 2–5 × 2–10 cm, not fleshy, base cordate, margins crenate to serrate, ciliate or eciliate, apex acute to obtuse or rounded, surfaces usually pubescent, rarely glabrous.
basal and cauline;
basal: 2–3(–4);
stipules ovate-lanceolate, ovate, or oblong, margins entire, apex ± acute;
petiole 1.5–15 cm, glabrous;
blade broadly reniform to orbiculate, 0.5–4.6 × 0.9–6.4 cm, base cordate, margins crenate to crenate-serrate, ciliate, apex obtuse, rounded, or truncate, rarely with terminal point, abaxial surface sparsely puberulent on veins, adaxial surface glabrate to ± densely puberulent;
cauline similar to basal except: stipules lanceolate, ovate, or oblong, margins entire to erose, apex acute to obtuse;
petiole 0.3–7(–10) cm;
blade sometimes ovate, 0.8–3.7 × 1–4.8 cm.
3–25 cm, glabrous or sparsely pubescent.
2–9 cm, usually glabrous.
sepals lanceolate to ovate, margins ciliate or eciliate, auricles 1–2 mm;
petals light to dark blue- or dark purple-violet, reddish purple, or rarely white on both surfaces, usually white basally, lowest and sometimes lateral 2 purple-veined, lateral 2 bearded, lowest bearded or beardless, 15–25 mm, spur same color as petals, gibbous, 2–3 mm;
style head beardless; cleistogamous flowers on prostrate to ascending peduncles.
sepals with or without purple stripe on both sides of midvein, narrowly lanceolate to oblong, margins ciliate or eciliate, auricles 0.5–1 mm;
petals deep lemon-yellow on both surfaces, lower 3 and often upper 2 brownish purple-veined, lateral 2 beardless, lowest 6–15 mm, spur yellow to yellowish green, gibbous, 2–2.5 mm;
style head beardless; cleistogamous flowers axillary.
ellipsoid, 5–12 mm, glabrous.
oblong-ovoid, 3–6 mm, glabrous or sparsely pubescent.
beige, mottled to bronze, 1.5–2.5 mm.
purple, sometimes streaked with light and dark brown, 1.5–2.5 mm.
= 54.
Viola sororia
Viola biflora
Viola sororia is similar to V. palmata in the high degree of phenotypic plasticity. The petal color is usually light to dark blue-violet. In V. sororia forma priceana (the Confederate violet) petals are grayish white with violet veins. Viola septentrionalis was recognized by N. L. Gil-Ad (1997) based on what he considered distinct capsule and seed morphology. His assumptions were based on one to four specimens. A. Haines (2011) alluded to the variability of V. sororia and indicated that a more northern form has often been called V. septentrionalis. He suggested that range-wide patterns of variation make it difficult or impractical to separate. We currently see no valid reason to recognize V. septentrionalis.
Viola floridana was recognized by D. B. Ward (2006) as distinct from V. sororia based on being glabrous except for scattered hairs on petioles.
Viola sororia reportedly hybridizes with V. cucullata (= V. ×bissellii House), V. hirsutula [= V. ×cordifolia (Nuttall) Schweinitz], V. pedatifida var. brittoniana (= V. ×insolita House), V. pedatifida var. pedatifida (= V. ×bernardii Greene), and V. sagittata var. sagittata (= V. ×conjugens Greene).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 5 (2 in the flora).
Viola biflora may be the most widely distributed species of the genus in the Northern Hemisphere. Although occurring most often in mountainous areas at high elevations, it is known from Alaska near the coast at elevations of ca. 45 m (PNW Herbaria Portal 2010) and has been reported from lowland meadows in Kamchatka (V. B. Baird 1942), and is occasionally found near sea level in exposed rocky habitats on the west coast of the Queen Charlotte Islands (R. A. Calder and R. L. Taylor 1968).
Sometimes described as high latitude, circumpolar, Viola biflora also occurs in mid latitudes north of the equator. It is not truly circumpolar; it does not occur in eastern Canada or in Greenland. The deeply cleft style head sets V. biflora apart from all other species in North America. V. B. Baird (1942) suggested that the occasional presence of two cleistogamous flowers in the axil of the same leaf may account for the name “biflora.”
H. N. Ridley (1930) said that in Europe, deer (Cervus dama Linnaeus and Rangifer tarandus Linnaeus) may play a role in the dispersal of Viola biflora; seeds have been recovered from their droppings.
Nonflowering Viola biflora can be confused with V. renifolia where their ranges overlap in Yukon, Alaska, and Colorado.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lowest petal 6–10 mm; seeds 1.5–2 mm; sepals usually without purple stripe; Yukon, Alaska, Colorado. | var. biflora |
1. Lowest petal 11–15 mm; seeds 2.5 mm; sepals usually with purple stripe; Queen Charlotte Islands, Vancouver Island, British Columbia. | var. carlottae |
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