Keys to the Genus Viola
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Key to Viola keys
| 1a | Plant caulescent, producing aerial stems bearing leaves and flowers or capsules at nodes | 2 |
| 1b | Plant acaulescent, with leaves and flowers or fruits arising directly from the rootstock (yellow-flowered V. rotundifolia is acaulescent during spring flowering but produces a stolon-like prostrate stem with 0–1 leaf and 1–3 capsules in summer, and is inserted in Keys C and D) | 3 |
| 2a (1) | Corolla yellow or white with a yellow throat (sometimes fading or drying to lavender), ventral surface of petals commonly pink- or purple- to brown-tinged); stipules membranous or partially to wholly herbaceous, margins entire or erose | |
| Key A | ||
| 2b | Corolla cream or pale blue or multicolored (violet to purple with orange or yellow) with a yellow throat, or cream-white, pale blue or violet to purple with a white throat, ventral surface not differently tinged; stipules herbaceous, margins fringed or deeply lobed | |
| Key B | ||
| 3a (2) | Plant growing from horizontal stoloniform rhizome, producing surficial or subsurficial stolons especially in summer, rhizome and/or stolons < 3 mm in diameter (rhizome ≥ 3 mm in summer fruiting V. rotundifolia, stolons lacking in V. renifolia and commonly lacking in V. vittata); corolla white with greenish-white throat, mostly < 1 cm long (violet in V. palustris, white or purple and > 1 cm in V. odorata) | |
| Key C | ||
| 3b | Plant growing from ascending to vertical thickish sometimes branched rhizome commonly ≥ 3 mm in diameter, lacking stolons; corolla blue or violet to purple (white with blue, blue-gray or purple eyespot in V. communis f. priceana, white with partial purple eyespot in V. floridana “peninsular Florida”, white in rare albinos of various species), > 1 cm long (yellow and up to 1.4 cm in V. rotundifolia) | |
| Key D |
Key A—Caulescent violets with white or yellow flowers, and entire or erose stipules
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| 1a | Corolla white with a yellow center, ventral surface of petals pink- or violet-tinged, dorsal surface of aging flowers fading to pink or violet; stipules long-triangular, attenuate | 2 |
| 1b | Corolla yellow, ventral surface of petals often brown-tinged; stipules ovate to narrowly ovate | 3 |
| 2a (1) | Plants not densely colonial, rhizome short, lacking an elongate stoloniform extension (s. Appalachian plants sometimes produce a stoloniform rhizome); Foliage nearly glabrous or petioles and lower surface of leaf blades sparsely hirtellous; upper leaf blades long-acuminate at apex, lower subacuminate; calyx glabrous and eciliate, sepals linear-lanceolate; interruptedly transcontinental, e. North America west to e. WI and IN, mostly absent from the Great Plains, widespread in the Rocky Mountains south to n. Mexico | |
| Viola canadensis L. | ||
| 2b | Plants commonly densely colonial, rhizome continuing in an elongate stoloniform extension that often terminates in a plantlet; Foliage moderately to densely hirtellous or hirsute; upper leaf blades subacuminate to acute at apex, lower acute to obtuse; calyx typically hirtellous and ciliate, sepals lanceolate; Great Plains east to s. WI and nw. IL | |
| Viola rugulosa Greene | ||
| 3a (2) | One or more cauline leaf blades deeply 3- or 5-lobed; nectarguide-lines of chasmogamous flower extending > 2/3 length of the spurred petal | |
| Viola tripartita Elliott | ||
| 3b | Leaf blades unlobed; nectarguide-lines extending ≤ 1/2 length of spurred petal | 4 |
| 4a (3) | Leaf blades as broad as long or broader than long | 5 |
| 4b | Leaf blades distinctly longer than broad | 6 |
| 5a (4) | Stems mostly 2 to several, usually decumbent at base during chasmogamous flowering, becoming erect in fruit; basal leaves (1)2–5; cauline leaves distributed over much of stem length, ovate, cordate at base, acute to abruptly short-acuminate at apex; foliage glabrous or thinly pubescent on upper stem and leaves; stipules narrowly ovate; upper surface of leaf blades medium green | |
| Viola eriocarpa Schwein. | ||
| 5b | Stems 1(2), erect throughout the growing season; basal leaves 0(–2); cauline leaves clustered in uppermost 1/4 of stem length, broadly ovate to reniform, subcordate to broadly cuneate at base, broadly obtuse to rounded at apex; foliage densely pubescent throughout; stipules broadly ovate; upper surface of leaf blades gray-green | |
| Viola pubescens Aiton | ||
| 6a (5) | Rhizome whitish; leaf blades hastate, base subcordate to deeply cordate with basal lobes parallel or divergent; upper surface of leaf blades in life frequently bicolorous, silvery-green between the contrasting darker green veins | |
| Viola hastata Michx. | ||
| 6b | Rhizome brown; leaf blades lanceolate, ovate-lanceolate, elliptical, lance-triangular to rhombic-lanceolate or narrowly ovate, base rounded or cuneate to truncate; leaf blade surfaces uniformly green | 7 |
| 7a (6) | Foliage green; leaf blades narrowly ovate or lance-triangular to rhombic-lanceolate, margins serrate at least near middle of blade; forests of eastern N America | 8 |
| 7b | Foliage gray-green; leaf blades linear-lanceolate to lanceolate, narrowly ovate or elliptical, margins subentire (crenate to serrate in elliptical-leaved V. praemorsa); grasslands and desert scrub of Great Plains and w. North America | 9 |
| 8a (7) | Leaf blades narrowly ovate, broadest well above the base, base cuneate to broadly rounded; margins conspicuously serrate to the tip; stem, foliage and peduncles glabrous or sparsely to moderately hirtellous with easily visible hairs; north of GA and SC | |
| Viola glaberrima (Ging. ex Chapm.) House | ||
| 8b | Leaf blades lance-triangular to rhombic-lanceolate, broadest just above the base, base broadly cuneate to truncate; apical portion beyond broadest point of blade subentire; stem, foliage and peduncles minutely puberulent with hairs requiring magnification to see; mostly south of TN and NC | |
| Viola tenuipes Pollard | ||
| 9a (8) | Leaf blades linear-lanceolate to lanceolate, ≥ 3.5 times as long as wide | |
| Viola nuttallii Pursh | ||
| 9b | Leaf blades narrowly ovate or elliptical, < 2.6 times as long as wide | 10 |
| 10a (9) | Leaf blades elliptical, base rounded to cuneate, margins crenate to serrate; foliage hirtellous | |
| Viola praemorsa Douglas ex Lindl. subsp. praemorsa | ||
| 10b | Leaf blades narrowly ovate, base mostly truncate to subcordate, margins subentire; foliage puberulent | |
| Viola vallicola A.Nelson var. vallicola |
Key B—Caulescent violets with whitish to pale blue, violet, purple or multicolored flowers, and fringed or lobed stipules
[back to Key to Viola keys]
| 1a | Corolla strongly frontally flattened in life; petals cream or pale blue to purple, red to orange or multicolored with yellow throat; spur short, up to 3 mm long; stipules deeply pinnately lobed with few to many lateral segments, the terminal lobe resembling the leaf blades; leaf blades linear-lanceolate to elliptical, base cuneate to truncate; plants annual or biennial, with slender rootstock | 2 |
| 1b | Corolla not strongly frontally flattened in life; petals cream, pale blue or violet to purple with white throat; spur longer, 3–20 mm long; stipules subentire to irregularly lacerate or laciniate but not deeply lobed with leaf-like terminal lobe; leaf blades ovate to reniform, base cordate; plants perennial, with thickish rootstock | 5 |
| 2a (1) | Petals shorter than the sepals or scarcely surpassing them by 1–2 mm, cream-white; sepals nearly or fully concealing capsule | |
| Viola arvensis Murray | ||
| 2b | Petals well surpassing sepals, pale blue to violet (infrequently cream-white) or multicolored; sepals neither surpassing nor concealing capsule | 3 | 3a (2) | Leaves all cauline; petals pale blue to violet or cream-white; terminal lobe of stipules slightly larger than lateral lobes, similar in shape, with 0–3 crenations per margin; quadrate stems recurved-puberulent or -hispidulous on face directly above a leaf node but essentially glabrous on the other faces; capsules < 6 mm; seeds 1.2–1.5 × 0.6–0.8 mm; cleistogamous flowers produced; native of diverse situations, especially in alkaline floodplains |
| Viola rafinesquei Greene | ||
| 3b | Leaves cauline and basal; petals variously colored, distal half of upper pair of petals purple-black or borders of all petals black; terminal lobe of stipules much larger and differently shaped than lateral lobes, with (2–)4 or more crenations per margin; quadrate stems recurved-puberulent on the angles or strictly glabrous; capsules 6–10 mm long; seeds 1.4–1.7 × 0.8–0.9 mm; cleistogamous flowers lacking; cultivated plants of abandoned homesteads, roadsides and cemeteries | 4 |
| 4a (3) | Flowers ≤ 1 cm long; lower three petals cream-white, upper two purple-black at least in distal half; occasional escape | |
| Viola tricolor L. | ||
| 4b | Flowers > 1.5 cm long; all petals variously colored, often with broad black border; barely persistent following cultivation | |
| Viola ×wittrockiana Gams ex Nauenb. & Buttler | ||
| 5a | Current year’s stems ascending at chasmogamous flowering time, persistent through winter become prostrate and root at the nodes, generating the following year's plants at their tips (plants thus mat-forming) | 6 |
| 5b | Stems ascending to erect at chasmogamous flowering time through fruiting, deciduous and not rooting at nodes (plants thus solitary) | 7 |
| 6a (5) | Foliage glabrous except for small scattered subappressed hairs on upper surface of leaf blades (especially near the margins), peduncles and stems glabrous; upper surface of leaf blades uniformly green; stipules weakly lacerate, with marginal processes < 1/4 as long as the stipule; moist loam of riverbanks and lawns, PA and WV, disjunct in w. NC | |
| Viola appalachiensis L.K.Henry | ||
| 6b | Foliage, peduncles and stems densely puberulent; upper surface of leaf blades silvery- to gray-green with darker green veins; stipules deeply laciniate with marginal processes > 1/2 as long as the stipule; sandy loam, commonly on dolomite ledges in dry-mesic and mesic forests in the north part of the range and under dry oak-pine forests southward, e. WV, w. VA and c. OH south to FL, AR and e. TX | |
| Viola walteri House | ||
| 7a (5) | Corolla pale violet with purple-black eyespot; spur 10–15 mm, as long as or longer than blade of bottom petal; all petals glabrous; stipules oblong- to linear-lanceolate, > 3 × as long as broad, weakly lacerate; margins of leaf blade remotely crenate-serrate | |
| Viola rostrata Pursh | ||
| 7b | Corolla blue to purple, or cream-white, nectarguides fine and inconspicuous, lacking a dark eyespot; spur short or elongate but distinctly shorter than blade of bottom petal; lateral petals bearded; stipules lanceolate to ovate, < 3 × as long as broad, weakly to strongly lacerate or laciniate; margins of leaf blades closely crenulate, crenate or subentire | 8 |
| 8a (7) | Corolla cream-white; calyx ciliate; auricles prominent and quadrate; margins of leaf blades closely crenulate; stipules strongly lacerate | |
| Viola striata Aiton | ||
| 8b | Corolla blue to purple; calyx eciliate (midvein of sepals sometimes puberulent in V. adunca); auricles short and rounded; margins of leaf blade subentire, rounded-dentate or (sub)crenate; stipules minutely toothed or lacerate to strongly laciniate | 9 |
| 9a (8) | Foliage, stems and peduncles puberulent (very rarely glabrous in boreal populations); margins of leaf blades subentire to subcrenate, commonly revolute; stipules strongly laciniate | 10 |
| 9b | Foliage glabrous except for small scattered subappressed hairs on upper and/or lower surface of leaf blades, stems and peduncles glabrous; stipules minutely toothed or weakly lacerate | 11 |
| 10a (9) | Style abruptly expanding just below head; projections on head (when present) commonly dense, narrowly cylindrical, their length up to 1/6 the width of the style head; tip below stigmatic orifice abruptly bent upward at 90 °; hairs of foliage and peduncle (when present) up to 0.3 mm long; guard cells 22-30 µm long; pollen grains 3.2-4.6 µ in diameter; widely distributed n. and e. of Lake Superior, and mostly s. of the U.S.-Canadian border in the West | |
| Viola adunca Sm. | ||
| 10b | Style uniformly cylindrical or gradually expanding to head; projections on head (when present) sparse, conical or globular, their length up to 1/10 the width of the style head; tip below stigmatic orifice gradually bent upward at 45 °; hairs of foliage and peduncle (when present) up to 0.22 mm long; guard cells 25-36 µm long; pollen grains 4.1-4.9 µ in diameter; virtually restricted to c. and w. Canada, from n. shore of Lake Superior west to YUK and Vancouver Island, BC. | |
| Viola aduncoides A.Löve & D.Löve | ||
| 11a (9) | Basal leaves absent; leaf blades narrowly ovate to ovate, distinctly longer than broad, base truncate to cordate, apex acute to narrowly obtuse; spur white to light blue; s. Greenland | |
| Viola canina L. | ||
| 11b | Basal leaves present; leaf blades broadly ovate, orbicular or reniform, as broad as long or broader than long, base cordate, apex broadly rounded or apiculate at apex, cordate at base; spur white to light blue; widely distributed but absent from Greenland | |
| Viola labradorica Schrank |
Key C—Acaulescent violets with horizontal stoloniform rhizomes and/or stolons (stolons lacking in V. renifolia, commonly lacking in V. vittata), and white or purple flowers
[back to Key to Viola keys]
| 1a | Flower > 1 cm long; corolla violet (often white in V. odorata); plant rosulate and producing greenish leafless non-reproductive stolons terminating in a plantlet, or growing from a creeping pale rhizome that produces leaves, flowers and capsules along its length near the apex | 2 |
| 1b | Flower mostly ≤ 1 cm long; corolla white; plant rosulate, producing stolons with leaves, flowers and/or capsules, especially during summer fruit, or terminating in a plantlet (stolons lacking in V. renifolia, commonly lacking in V. vittata) | 4 |
| 2a (1) | Plant rosulate, growing from vertical or stoloniform rhizome with pale to greenish subherbaceous stipules, producing leafless and non-reproductive, greenish, cord-like stolons; foliage puberulent; corolla white or violet; style of chasmogamous flower with a pronounced downward-pointing hook; cleistogamous capsule purple-spotted or blotched, hirtellous; Eurasian escape to lawns, roadsides and urban woodlots | |
| Viola odorata L. | ||
| 2b | Plant growing from a creeping pale sometimes branching rhizome with pink or brownish membranous stipules, producing leaves, flowers and capsules along its length; foliage essentially glabrous; style of chasmogamous flower lacking a pronounced downward-pointing hook; cleistogamous capsule unspotted, glabrous; native of bogs and sedge meadows in arctic and boreal North America, south to ME, VT, MI and MN, CO, AZ and n. CA | 3 |
| 3a (2) | Leaves during chasmogamous flower 1–2, blades 8–25 mm long during chasmogamous flower, strictly glabrous or lower surface with fine hairs along proximal veins; bracts positioned above the middle, often near the apex of the peduncle; lateral petals sparsely bearded within; spur ca. 1.5 mm long, 2–3 × as long as auricles; style and stamen appendages prominently exserted and fully visible in life; seeds dark gray to olive-green, blotched | |
| Viola epipsila Ledeb. subsp. repens W.Becker | ||
| 3b | Leaves during chasmogamous flower 2–5, blades 25–50 mm long, strictly glabrous; bracts positioned at or below middle of peduncle; lateral petals glabrous within; spur ca. 2.0 mm long, 1.5 × as long as auricles; style and stamen appendages weakly exserted and scarcely visible in life; seeds very dark brown to black, unspotted | |
| Viola palustris L. subsp. palustris | ||
| 4a | Leaf blades distinctly longer than broad (1.5–15 × as long as broad), ovate-lanceolate to ovate-triangular, or lanceolate to linear | 5 |
| 4b | Leaf blades usually as broad as long or broader than long (< 1.2 × as long as broad), ovate or orbicular to reniform | 7 |
| 5a (4) | Largest leaf blades ovate-lanceolate to ovate-triangular, 1.5–2 × as long as broad, base broadly rounded to subcordate | |
| Viola primulifolia L. | ||
| 5b | Largest leaf blades lanceolate to linear-lanceolate in early chasmogamous flower, narrowly lanceolate to linear in fruit, 3–15 × as long as broad, base cuneate | 6 |
| 6a (5) | Largest leaf blades narrowly elliptical to lanceolate, 3–6(8) × as long as broad, (5)7–29 mm broad, often abruptly tapering to the petiole; gland of marginal teeth appressed to incurved, margins appearing subentire, low-serrate or (sub)crenate; summer plants producing surficial leafless or leafy stolons infrequently with 1–few cleistogamous capsules; lowest sepals of chasmogamous flowers narrowly triangular to ovate-triangular, acuminate; foliage glabrous (rarely sparsely hirtellous in extreme s. populations); widespread but absent from the extreme se. Atlantic Coastal Plain and Gulf Coastal Plains | |
| Viola lanceolata L. | ||
| 6b | Leaf blades linear to linear-lanceolate, 8–15 × as long as broad, (2)4–9(13) mm broad, tapering gradually to the petiole; gland of marginal teeth ascending to spreading, margins commonly appearing denticulate; summer plants rarely producing surficial stolons, these leafless and non-reproductive; lowest sepals of chasmogamous flowers linear-lanceolate to lance-triangular, acuminate to attenuate; foliage glabrous to moderately hirtellous; se. Atlantic and Gulf Coastal Plains | |
| Viola vittata Greene | ||
| 7a (4) | Plant growing from a vertical twisted rhizome, lacking stolons; leaf blades broadly ovate or suborbicular to reniform, widely spreading or more often lying on the substrate in life, especially during fruit, either entirely glabrous or densely hirsute on one or both leaf surfaces; lateral petals beardless within (rarely with a scant beard); cleistogamous capsule purple-spotted, on short prostrate peduncle; seeds orange-brown to brown | |
| Viola renifolia A.Gray | ||
| 7b | Plant growing from a horizontal stoloniform rhizome, producing surficial or subsurficial stolons especially during summer fruit (rhizome vertical in V. rotundifolia); leaf blades elevated and spreading in life, glabrous to variously pubescent (lying on the substrate in life, especially during fruit, in V. rotundifolia); lateral petals beardless or bearded; cleistogamous capsule unspotted on erect peduncle, or purple-spotted to blotched on prostrate peduncle; seeds tan or medium to dark brown or blackish-brown | 8 |
| 8a (7) | Rhizome vertical, ≥ 3 mm in diameter; leaf blades thickish in life, broadly elliptical to orbicular; stipules entire along margins; stolon-like summer stems bearing 0–1 leaf and terminating in a reduced cyme of 1–3 cleistogamous capsules purple-spotted or blotched; seeds ivory to light orange-brown | |
| Viola rotundifolia Michx. | ||
| 8b | Rhizome horizontal and stoloniform, < 3 mm in diameter; leaf blades thin in life, variously shaped; stipules glandular-fringed along margins; stolons leafless or bearing leaves and/or cleistogamous capsules at nodes along their length, sometimes terminating in a plantlet; cleistogamous capsules unspotted or spotted to blotched; seeds light brown to olive-brown or blackish | 9 |
| 9a (8) | Leaf blades uniformly green on both surfaces (lower surface sometimes drying orange-tinged), strictly glabrous (petioles may be glabrous or pubescent), orbicular, mostly broadly rounded at apex, margins subentire to shallowly crenate; cleistogamous capsules green, unspotted, on erect peduncles; seeds 0.8–1.4 × 0.7–0.8 mm, medium to dark olive-brown or brownish-black, with minute black spots | |
| Viola minuscula Greene | ||
| 9b | At least some leaf blades broader than long, bicolorous with darker green upper surface and paler lower surface, usually pubescent on one or both surfaces, obtuse to acute (acuminate) at apex, blade margins most often shallowly serrate; cleistogamous capsules with dense fine purple spots, on prostrate to arching peduncles; seeds 1.2–2.2 × 0.7–1.3 mm, brown or brownish-blackish, unspotted | 10 | 10a (9) | Leaves glabrous except for scattered appressed hairs on upper surface of leaf blades, peduncles glabrous; largest leaf blades abruptly acute at apex, inner edges of basal lobes attingent or overlapping in life, sinus < 1/4 length of blade, margins shallowly crenate; petioles and peduncles red-tinged or -spotted; all petals glabrous; cleistogamous capsules 6.5–8 mm long; seeds 1.2–1.3 × 0.7–0.8 mm, brownish-black; Appalachian Mountains and adjacent uplands, common at higher elevations |
| Viola blanda Willd. | ||
| 10b | Petioles and/or one or both surfaces of leaf blades glabrous or sparsely to densely hirsute, peduncles glabrous to hirsute; largest leaf blades typically obtuse to rounded at apex, inner edges of basal lobes well separated or divergent in life, sinus > 1/4 (often > 1/3) length of blade, margins low-serrate with noticeable teeth; petioles and peduncles not red-tinged or -spotted; lateral petals bearded; cleistogamous capsules 7–14 mm long; seeds 1.6–2.2 × 1.0–1.3 mm, light to medium brown; widely distributed in ne. North America, most common at lower elevations | |
| Viola incognita Brainerd |
Key D—Acaulescent violets lacking stolons, with blue or violet to purple flowers (yellow in V. rotundifolia, white with broad blue, blue-gray or purple eyespot in V. communis f. priceana, white with partial purple eyespot in V. "floridana “peninsular Florida")
[back to Key to Viola keys]
| 1a | Corolla yellow; leaf blades broadly elliptical to orbicular, nearly or completely prostrate on substrate, especially during fruit | |
| Viola rotundifolia Michx. | ||
| 1b | Corolla blue or violet to purple; leaf blades various (commonly prostrate on substrate during fruit in V. hirsutula and V. villosa, at least the outer leaves prostrate in V. fimbriatula) | 2 |
| 2a (1) | At least the largest leaf blades notched, incised, coarsely toothed, lobed or dissected, or bearing linear marginal processes | 3 |
| 2b | All leaf blades undivided, margins merely crenate or serrate (pectinately serrate in V. pectinata; occasional V. edulis in early chasmogamous flower without lobed leaf blades will key to Viola langloisii but has ovate-triangular sepals with shorter broader auricles < 2 mm long) | 34 |
| 3a (2) | All petals glabrous within; corolla concolorous blue or lower three petals blue and upper pair purple-black; stipules long-adnate to petiole; rhizome erect, barrel-like; cleistogamous flowers absent; dry sandy and gravelly soils in oak or oak-pine forests, barrens and sand prairies | 4 |
| 3b | Lateral petals bearded within, sometimes the spurred petal also; corolla concolorous except for expanded white area from the throat in a few species; stipules free; rhizome horizontal or ascending, sometimes branching, not barrel-like; cleistogamous flowers produced; diverse substrates and habitats | 6 |
| 4a (3) | Largest leaf blades oblanceolate to obspatulate or somewhat rhombic in outline, apically toothed or incised; Sandhills region of NC, SC, and GA | |
| Viola pedata L. var. flabellata D.Don | ||
| 4b | Largest leaf blades ovate to reniform in outline, pedately or triternately divided | 5 |
| 5a (4) | Largest leaf blades deeply triternately divided into numerous very narrowly linear ultimate segments; sw. NJ and se. PA to w. MD, south to w.-c. VA and se. WV | |
| Viola pedata L. var. cuneatiloba (Brainerd ex Fernald) H.E.Ballard, ined. | ||
| 5b | Largest leaf blades deeply pedately divided (rarely obrhombic or obovate and shallowly to moderately lobed due to partial fusion of leaf segments); widespread | |
| Viola pedata L. var. pedata | ||
| 6a (3) | Plant homophyllous, all blades lobed or dissected (plants with largest leaf blades shallowly lobed are frequent where V. sororia and other species with unlobed leaf blades are locally sympatric with species producing deeply divided leaves and are de novo hybrids; they will not key readily and must be inferred by association with the parent species) | 7 |
| 6b | Plant heterophyllous, producing leaf blades with lobes, coarse teeth or incisions during chasmogamous flowering and cleistogamous fruiting, and undivided leaf blades in very early spring and late autumn (often retaining one or more undivided blades) | 13 |
| 7a (6) | Petioles glabrous, leaf blades sparsely appressed-hirtellous on veins, margins appressed-ciliolate; spurred petal densely bearded; lowest sepals lanceolate, sharply acute; auricles prominent, elongating in fruit to 6 mm; cleistogamous capsules green drying tan, unspotted, on erect peduncles nearly or fully as long as petioles; seeds 1.3–2.0 × 0.9–1.3 mm, narrowly obovoid, medium brown to orange-brown, unspotted | 8 |
| 7b | Foliage glabrous or petioles and at least lower surface of leaf blades hirsute, margins often ciliate; spurred petal glabrous; lowest sepals oblong to ovate, obtuse to rounded at apex (lance- to ovate-triangular and acuminate in V. monacanora); auricles short and rounded, not elongating in fruit; cleistogamous capsules purple-spotted, on prostrate or arching peduncles shorter than petioles; seeds 1.6–2.4 × 1.1–1.7 mm, various but not medium brown to orange-brown, mostly spotted or blotched | 9 |
| 8a (7) | Largest leaf blades narrowly to broadly ovate in outline, base subtruncate to cordate, biternately divided into 7 or 9 ultimate lanceolate segments, terminal ultimate segment of terminal primary division commonly distinctly broader and well surpassing lateral segments; calyx eciliate or auricles infrequently irregularly ciliolate; seeds 1.3–1.9 × 0.9–1.3 mm; moist to wet sandy or peaty soils of brackish marshes, banks of streams and rivers, ditches along fields and in meadows, and forest clearings, Atlantic Coastal Plain | |
| Viola brittoniana Pollard | ||
| 8b | Largest leaf blades reniform in outline, base broadly rounded to subcordate, triternately divided into (13)17–25 narrowly linear ultimate segments, terminal ultimate segment of terminal primary division neither distinctly broader nor longer than lateral segments; calyx usually ciliate; seeds 1.7–2.0 × 1.1–1.3 mm; rich mesic loam of blacksoil prairies and savanna openings in the Midwest to the Great Plains and sw. North America, disjunct in s. ON and n. OH | |
| Viola pedatifida G.Don | ||
| 9a (7) | Foliage glabrous (petioles uncommonly sparsely hirsute in V. monacanora); calyx eciliate; lowest sepals acuminate; montane NC and VA | 10 |
| 9b | Foliage moderately to densely hirsute; calyx ciliate; lowest sepals ovate-lanceolate to broadly ovate, obtuse to broadly rounded (sometimes acute in V. baxteri) | 11 |
| 10a (9) | Largest leaf blades during chasmogamous flower narrowly ovate-triangular and palmatifid to subbiternate, blades in fruit ovate, biternately divided into 9–11(13) usually slightly falcate ultimate lobes, these becoming asymmetrically angulate at apex in fruit, outer margins of lobes with 1–3 incurved teeth, primary divisions not narrowed or constricted at base; lower surface of leaf blade not distinctly paler than upper, purple-tinged; lowest sepals lance- to ovate-triangular, acute or acuminate; seeds 1.8–2.1 × 1.2–1.4, blackish with minute raised black reticulations; moist loam soils in rich mesic rocky woodlands in the Blue Ridge Mountains of w. VA and nw. NC | |
| Viola monacanora J.L.Hastings & H.E.Ballard, ined. | ||
| 10b | Largest leaf blades during chasmogamous flower ovate and deeply bi- to subtriternately divided, blades in fruit orbicular to reniform and tri- to tetraternately dissected into 17–27 narrowly linear ultimate lobes, these narrowly rounded at apex, margins entire or with a minute subapical tooth on either margin, primary divisions distinctly constricted at base into a very slender elongate "petiolule"; lower surface of blade distinctly paler than upper, not purple-tinged; lowest sepals ovate-lanceolate to narrowly ovate, broadly acute to obtuse; seeds1.7–2.4 × 1.1–1.5 mm, gray, gray-brown, or light to medium (reddish-)brown, unspotted or with sparse to dense minute raised black spots; dry sandy shale-derived soils of woodland borders surrounding shale barrens in Allegany and Bath Cos., VA | |
| Viola tenuisecta Zumwalde & H.E.Ballard, ined. | ||
| 11a (9) | Largest leaf blades biternately to subtriternately divided into 9–13(15) narrowly linear-lanceolate lobes < 3 mm wide (in chasmogamous flower), the lateral second-order lobes of the terminal primary division attached medially, second-order lobes usually with a prominent slender spreading sharply acute tooth or short lobe on each side; primary divisions commonly narrowed at base to slender "petiolules"; foliage and peduncles not purple-tinged; lowest sepals acute or obtuse; seeds ivory, unspotted or occasionally with small weak light brown blotches or streaks; limestone prairies and prairie-like openings; lower elevations in e. Great Lakes region, w. NY to sw. ON and se. MI, south to sw. PA, sw. OH and ne. IN | |
| Viola baxteri House | ||
| 11b | Largest leaf blades (sub)biternately divided into 7 or 9 broadly linear or lanceolate lobes > 3 mm wide (in chasmogamous flower), the second-order lobes of the terminal primary division attached medially or basally, second-order lobes entire or with 1–2 inconspicuous short appressed or incurved teeth on each side; primary divisions not distinctly narrowed at base (distinctly narrowed in “Chapel Hill” variant); lower surface of leaf blades, petioles and peduncles often purple-tinged; lowest sepals obtuse to rounded; seeds light brown with small prominent dark orange-brown streaks, or light to medium gray with small prominent darker gray blotches or streaks; dry-mesic woodlands, not consistently associated with limestone; widely distributed in Appalachian Mountains and e. Piedmont, New England south to n. AL and se. TN | 12 |
| 12a (11) | Leaf blades subternately divided, secondary lobes on terminal primary division rhombic-lanceolate, divergent, lateral primary divisions rhombic in outline, all distinctly narrowed into a short “petiolule” at base, all lobes with an additional slender elongate lobe on outside margin (leaf vaguely resembling Anemone multifida); Piedmont of c. NC | |
| Viola "subsinuata Chapel Hill" | ||
| 12b | Leaf blades biternately divided, not usually narrowed into a distinct “petiolule” at base, secondary lobes of terminal primary division suberect or spreading, lobes entire or with a small subappressed tooth on outside margin; Appalachian Mountains and n. Piedmont | |
| Viola subsinuata (Greene) Greene [sensu stricto] | ||
| 13a (6) | At least some petioles prominently winged; lowest sepals linear-lanceolate to lance-triangular, acuminate; spurred petal bearded within; cleistogamous capsule unspotted, on erect peduncle (declined in V. fimbriatula); auricles prominent, elongating in fruit to 3 mm or more; in dry acidic sandy or gravelly soils in oak or oak-pine forests, barrens and forest borders, in the Atlantic Coastal Plain and Piedmont, Appalachian Mountains and s. Great Lakes regions | 14 |
| 13b | Petioles not prominently winged; lowest sepals lanceolate to (more commonly) ovate-lanceolate, oblong or ovate, acuminate to rounded; spurred petal glabrous or bearded within; cleistogamous capsule unspotted or purple-spotted or -blotched, on erect or declined to prostrate peduncle; auricles short and rounded or prominent, remaining short or weakly to strongly elongating in fruit; in diverse substrates and habitats, in various places in our region | 17 |
| 14a (13) | Foliage densely hirtellous, uniform green; at least the outer leaves widely spreading or prostrate on the substrate in life; petioles shorter than (in chasmogamous flower) to 2 × longer (in fruit) than blades; largest leaf blades broadly elliptical to narrowly oblong-ovate or narrowly ovate-triangular in outline, in fruit developing 1–2(3) coarse apically oriented basal teeth on each side; peduncle hirtellous; calyx ciliate; corolla purple, petals broadly rounded, spurred petal not medially compressed; peduncle of cleistogamous capsule declined; seeds 1.4–1.9 × 0.9–1.3 mm, medium to dark brown or gray-brown, unspotted or with small weak darker blotches | |
| Viola fimbriatula Sm. | ||
| 14b | Foliage glabrous or surfaces of leaf blades sparsely appressed-hirsute, blue-green, lower surface of blades, petioles and peduncles tinged with purple; leaves erect in life; petioles > 2 × as long as leaf blades; largest leaf blades narrowly ovate-triangular, triangular or deltate-triangular in outline, in flower or fruit developing 2–4 divergent narrowly elliptical to oblong lobes or slender linear processes on each side; peduncle glabrous; calyx eciliate; corolla violet, petals commonly emarginate, spurred petal commonly medially compressed; peduncle of cleistogamous capsule erect; seeds 1.4–2.2 × 0.9–1.5 mm, pinkish-gray to dark gray with prominent darker streaks and spots | 15 |
| 15a (14) | Largest leaf blades resembling a walkingstick insect (Diapheromera femorata), with main axis narrowly oblong-linear, each margin with 2–4 long slender variously bent processes; s.-c. VA and c. NC | |
| Viola "emarginata "entomophylla" | ||
| 15b | Largest leaf blades narrowly triangular to triangular-deltate in outline including lobes, with 2–3 basal narrowly elliptical or angulate oblong lobes on each side; widespread on Atlantic Coastal Plain and Piedmont | 16 |
| 16a (15) | Largest leaf blades triangular to triangular-deltate in outline, terminal primary division triangular, lacking medial lobes, each lateral primary division with 2–3 broad triangular basal lobes; widespread in ne. and mid-Atlantic Coastal Plain south through Piedmont of n. GA | |
| Viola emarginata (Nutt.) Leconte [sensu stricto] | ||
| 16b | Largest leaf blades (at least during cleistogamous fruit) broadly deltate to deltate-reniform, terminal primary division excluding lobes lanceolate, bearing 1–2 short medial lobes on each side of terminal primary division, each primary lateral division with 3–4 short oblong lateral lobes; Piedmont of c. and w. NC | |
| Viola "emarginata deltate" | ||
| 17a (13) | Largest leaf blades distinctly longer than broad (blade length:width ratio ≥ 1.3) | 18 |
| 17b | Largest leaf blades slightly longer than broad to broader than long (blade length:width ratio < 1.3) | 21 |
| 18a (17) | Leaves erect in life; leaf blades narrowly elliptical or ovate-lanceolate with small basal teeth or lobes during chasmogamous flower, sagittate or lance-triangular with larger slender basal teeth or linear-falcate lobes during fruit, teeth or lobes ≤ 1/4 length of the midrib; foliage glabrous or (more commonly) sparsely to moderately hirtellous; lowest sepals linear-lanceolate to lance-triangular; spurred petal densely bearded within; inhabiting upland or wetland sites in dry to seasonally moist acidic sandy soils in sand prairies and oak barrens, interdunal swales, and lakeshores; widespread throughout much of e. North America, mostly absent from Atlantic and Gulf Coastal Plains | |
| Viola sagittata Aiton | ||
| 18b | Leaves erect or widely spreading in life; leaf blades narrowly ovate-triangular to narrowly ovate or broadly oblong-lanceolate, lateral lobes short and rounded (in V. pedatiloba), short and angulate during chasmogamous flower but elongating to ≥ 1/4 length of the midrib in fruit (in V. edulis), or variously short and elliptical or longer and linear and ≥ 1/4 length of the midrib (in V. viarum); foliage strictly glabrous; lowest sepals linear-lanceolate to ovate-triangular; spurred petal glabrous or sparsely bearded within; inhabiting diverse substrates of bottomland sites along streams and rivers of the Atlantic and Gulf Coast or central and lower Midwest | 19 |
| 19a (18) | Leaves ascending to erect in life; leaf blades ovate-triangular to narrowly ovate, slender lateral lobes already 1/4–1/2 midrib length during chasmogamous flower; lowest sepals linear-lanceolate to lanceolate; spurred petal sparsely bearded within; inhabiting thin alluvial soils amid limestone gravel or rubble or cracks in limestone bedrock along streams and rivers, mainly in the n. Ozarks and Missouri River drainage of the central and lower Midwest | |
| Viola viarum Pollard | ||
| 19b | Leaves widely spreading in life; leaf blades narrowly ovate-triangular or broadly oblong-lanceolate, lateral lobes short and rounded (in V. pedatiloba) or short and angulate during chasmogamous flower and elongating during fruit (in V. edulis); lowest sepals ovate-triangular; spurred petal glabrous within; inhabiting floodplains of streams and rivers along the Atlantic and Gulf Coastal Plains | 20 |
| 20a (19) | Leaf blades narrowly ovate-triangular in chasmogamous flower, broadening to ovate in fruit; lateral lobes angulate; blade margins incurved-serrate; seeds brown with dense minute black spots or reticulations; e. Atlantic Coastal Plain | |
| Viola edulis Spach | ||
| 20b | Leaf blades broadly oblong-lanceolate; lateral lobes rounded; most of blade margins subentire, outer margins of lateral lobes prominently crenulate; seeds blackish; w. side of Mississippi embayment in e.-c. AR, se. LA | |
| Viola pedatiloba (Brainerd) Burwell & H.E.Ballard, ined. | ||
| 21a (17) | Foliage glabrate, puberulent or hirsute (occasionally essentially glabrous in V. stoneana); peduncles glabrous or sparsely to moderately hirsute; calyx eciliate or ciliate; lowest sepals linear-lanceolate to ovate, acuminate to rounded; auricles short and rounded and not elongating in fruit (prominent and weakly elongating in fruit in V. stoneana); cleistogamous capsule finely to heavily purple-spotted or -blotched, on initially prostrate peduncle arching upward just before dehiscence, peduncle much shorter than petioles (peduncle ascending to erect and as long as or longer than shorter petioles in V. stoneana) | 22 |
| 21b | Foliage strictly or essentially glabrous; peduncles glabrous; calyx eciliate; lowest sepals acute or acuminate; auricles short and not elongating in fruit, or prominent and elongating in fruit; cleistogamous capsule unspotted or finely to heavily spotted or blotched with red, reddish-purple or purple, on erect or suberect peduncle, peduncle as long as or longer than shorter petioles (prostrate or arching upward and much shorter than petioles in V. "Gulf Coastal Plains edulis" and V. egglestonii) | 29 |
| 22a (21) | Largest lobed leaf blades biternately divided, the terminal primary division bearing lateral lobes (veins of these lateral lobes will connect with the midrib or with veins of the terminal primary division) | 23 |
| 22b | Largest lobed leaf blades pedately divided, the terminal primary division lacking lateral lobes (any shorter intermediary lobes between the terminal and lateral primary divisions will have veins connecting to the veins of the lateral primary divisions) | 25 |
| 23a (22) | Central and lateral lobes of terminal primary division rhombic-lanceolate, lateral lobes inserted well above the base of the central lobe, widely divergent; base of terminal and lateral primary divisions usually constricted to a slender elongate "petiolule"; foliage essentially glabrous, or petioles and lower surface of leaf blades sparsely hirsute and margins of blades sparsely ciliolate; chasmogamous and cleistogamous peduncles glabrous; calyx eciliate; lowest sepals lance-triangular, acuminate; seeds ivory to tan or light gray-brown, unspotted or with weak brown rectangular blotches; rich mesic forests along "fall line" between lower Piedmont and upper Atlantic Coastal Plain, NJ south to c. VA, disjunct in e.-c. NC | |
| Viola stoneana House | ||
| 23b | Central and lateral lobes of terminal primary division linear-lanceolate to lanceolate, lateral lobes inserted near or just above the base of the central lobe, strongly ascending to widely divergent; base of primary divisions not or only weakly constricted to a slender “petiolule”; petioles and lower surface of leaf blades sparsely to densely hirtellous or hirsute, margins of blades ciliate; chasmogamous and cleistogamous peduncles glabrous or hirsute; calyx ciliate; lowest sepals linear-lanceolate to ovate, acuminate or acute to rounded; seeds pale golden-yellow or tan to light red-brown with small weak or prominent streaks and blotches; Appalachian Mountains, or Gulf Coastal Plain and Mississippi Embayment region | 24 |
| 24a (23) | Lateral lobes of terminal primary division suberect or strongly ascending to somewhat spreading; foliage hirsute; chasmogamous and cleistogamous peduncles glabrate to hirsute; lowest sepals relatively short, lanceolate or lance-triangular to ovate, acuminate to obtuse or rounded; Appalachian Mountains, from s. PA south to w. NC | |
| Viola "palmata pseudo-stoneana" | ||
| 24b | Lateral lobes of terminal primary division widely divergent; foliage sparsely to moderately hirtellous; chasmogamous and cleistogamous peduncles glabrous; lowest sepals elongate, linear-lanceolate, acuminate; Gulf Coastal Plain and Mississippi Embayment region, w. GA to c. AR | |
| Viola "palmata Red Hills" | ||
| 25a (22) | Foliage glabrate or puberulent; chasmogamous and cleistogamous peduncles glabrous; n. AL and n. GA, or w. Gulf Coast region and Lower Midwest | 26 |
| 25b | Foliage moderately to densely hirsute; chasmogamous and cleistogamous peduncles nearly glabrous or sparsely to moderately hirsute; Ridge and Valley Province of w. VA, or widespread in eastern North America | 27 |
| 26a (25) | Foliage puberulent; terminal lobe of terminal primary division triangular and distinctly broader than lateral lobes; calyx eciliate; spurred petal glabrous or sparsely bearded within; s. & w. AR to c. OK, south to se. LA and s.-c. TX | |
| Viola lovelliana Brainerd | ||
| 26b | Foliage essentially glabrous or sparsely hirsute (especially on petioles and lower surface of leaf blades); all lobes of terminal and lateral primary divisions approximately equal in size and shape; spurred petal glabrous within; n. AL and n. GA | |
| Viola "palmata glabrate" | ||
| 27a (25) | Larger leaf blades shallowly to moderately divided into 3 or 5 lobes, central lobe of terminal primary division narrowly ovate or ovate-triangular, significantly larger than lateral primary lobes or intermediary lobes between terminal and lateral primary divisions, primary divisions separated by sinuses not usually > 2/3 the distance to petiole summit (shallowly lobed plants in the range of V. palmata var. dilatata are probable de novo hybrids with V. sororia and other species with unlobed leaf blades); peduncles essentially glabrous or sparsely hirsute; ne. US and s. ON southward into the s. Appalachian Mountains and associated uplands, mostly absent from Lower Piedmont and se. Atlantic Coastal Plain, the s. limit in the Gulf States and Lower Midwest unclear | |
| Viola palmata L. var. triloba (Schwein.) Ging. | ||
| 27b | Larger leaf blades deeply divided into (3) 5 or 7 lobes, lobes approximately equal in size and length, primary divisions separated by sinuses nearly or fully to petiole summit; peduncles moderately hirsute; w. VA, or Piedmont, Atlantic and Gulf Coastal Plains, and Lower Midwest | 28 |
| 28a (27) | Uppermost lobes of lateral primary divisions (or longest axis of lateral primary divisions if not deeply cleft or divided) spreading to ascending, lateral primary divisions sometimes scarcely to weakly cleft and appearing falcate, lunate or “dilated”, the smallest lowest lobes at the base of the lateral primary division (if any) not usually overlapping in life; foliage, peduncles and calyces gray-green to medium green, commonly lacking red-purple or purple pigmentation; chasmogamous and cleistogamous peduncles and calyces green; widespread at lower elevations of Piedmont and Atlantic and Gulf Coastal Plains in se. U.S, and Lower Midwest | |
| Viola palmata L. var. palmata | ||
| 28b | Uppermost lobes of lateral primary divisions widely divergent, lateral primary divisions always deeply bilobate into two major lobes, the lowest major lobe with a third small lobe near the base, these smallest lobes overlapping in life; foliage color gray- or blue-green, lower surface of leaf blades strongly tinged with purple, peduncles and calyces strongly spotted with red-purple or purple; sporadic and rare in Ridge and Valley province of the Appalachian Mountains in w. VA | |
| Viola "palmata avipes" | ||
| 29a (21) | Largest leaf blades deeply biternately divided nearly to petiole summit into 7 or 9 lobes (biternately divided leaf blades occasionally produced by V. septemloba, which is keyed out in 21b), the terminal primary division narrowly lanceolate and not much broader than its lateral lobes or the lobes on the lateral primary divisions; lowest sepals oblong-lanceolate to ovate, obtuse to broadly rounded; auricles short and rounded, not elongating in fruit; spurred petal sparsely to densely bearded within; cleistogamous capsule unspotted, on prostrate to arching peduncle much shorter than petioles; seeds 2.2–2.7 × 1.5–1.7 mm, medium to dark brown, unspotted; upland limestone cedar glades of Interior Highlands region, s. IN south to nw. GA and n. AL | |
| Viola egglestonii Brainerd | ||
| 29b | Largest leaf blades shallowly to deeply pedately divided into 3–7(9) lobes (biternately divided leaf blades occasionally produced by V. septemloba), the terminal primary division broadly oblong to ovate or rhombic-ovate, distinctly to much broader than any intermediary lobes between the terminal and lateral divisions; lowest sepals lanceolate to ovate-triangular, acuminate (oblong-lanceolate to ovate and obtuse to rounded in V. "Gulf Coastal Plain edulis"); auricles prominent, weakly to strongly elongating to 3 mm in fruit; spurred petal glabrous within (sparsely bearded in V. viarum, densely bearded in V. septemloba); cleistogamous capsules unspotted, on peduncles as long as or longer than the petioles (capsule heavily spotted or blotched, on prostrate or arching peduncle shorter than the petioles in V. "Gulf Coastal Plain edulis"); seeds dark bronze and unspotted, or brown with minute black spots or reticulations; inhabiting pine savannas (V. septemloba) or bottomland sites along streams and rivers, Atlantic and Gulf Coastal Plains and lower Midwest Missouri River drainage | 30 |
| 30a (29) | Largest leaf blades moderately to deeply (3)5- or 7(9)-lobed, lobes elliptical, lobes divergent on blades with 5 or more lobes, lowest lobe downward-pointing; blade margins entire or subentire; spurred petal densely bearded; cleistogamous capsule unspotted, on tall erect peduncle surpassing some petioles; seeds (1.5)1.9–2.5 × 1.4–1.6 mm, brownish-black, unspotted; dry to seasonally moist sand of frequently burned long-leaf pine savannas | |
| Viola septemloba Leconte | ||
| 30b | Largest leaf blades shallowly to deeply 3- to 7-lobed, lobes linear or angulate, elliptical, ovate or rhombic-ovate, lobes ascending to spreading on blades with 5 or more lobes, lacking a distinct downward-pointing lobe; blade margins incurved-serrate; spurred petal glabrous within (sparsely bearded in V. viarum); cleistogamous capsule unspotted or finely to heavily spotted or blotched with red or purple, on ascending to erect peduncle surpassing some petioles or on prostrate peduncle much shorter than petioles; seeds various; bottomland sites in diverse substrates along rivers and streams or swamps | 31 |
| 31a (30) | Leaves ascending to erect in life; lowest sepals linear-lanceolate to lanceolate; spurred petal sparsely bearded within; cleistogamous capsule finely spotted with red or purple, on ascending to erect peduncle equaling or surpassing shorter petioles; inhabiting thin alluvial soils amid limestone gravel or rubble or cracks in limestone bedrock along streams and rivers, mainly in the n. Ozarks and Missouri River drainage of the central and lower Midwest | |
| Viola viarum Pollard | ||
| 31b | Leaves widely spreading to erect in life; lowest sepals oblong to ovate-triangular; spurred petal glabrous; cleistogamous capsule unspotted or spotted, on ascending to erect peduncle equaling or surpassing petioles or on prostrate peduncle much shorter than petioles; inhabiting sandy or silty soils of floodplains, swamps and hammocks on the Atlantic and Gulf Coastal Plains | 32 |
| 32a (31) | Petioles and leaves widely spreading in life; leaf blades during chasmogamous flower with any intermediary lobes between terminal and primary divisions very short, ≤ 1/4 length of the midrib; most deeply divided leaf blades with 3–5 lobes; sepals > 2/5 length of the dehisced capsule; auricles moderately elongating to 3 mm; cleistogamous capsule unspotted, on erect peduncle; seeds brown with minute raised black spots or reticulations; Atlantic Coastal Plain, s. MD south to se. GA | |
| Viola edulis Spach | ||
| 32b | Petioles and leaves ascending in life; leaf blades during chasmogamous flower with any intermediary lobes between terminal and primary divisions mostly elongate ≥ 1/4 length of the midrib; most deeply divided leaf blades with 5–7 lobes; sepals ≤ 2/5 length of the dehisced capsule; auricles not or only weakly elongating to 1–1.5(2) mm; cleistogamous capsule finely to heavily spotted or blotched, on ascending peduncle equaling or surpassing shorter petioles or prostrate and much shorter than peduncles; seeds dark bronze and unspotted, or light brown with brown streaks or blotches; FL and Gulf Coastal Plain | |
| 33a (32) | Auricles weakly elongating in fruit to 1.5–3 mm; cleistogamous capsule finely spotted with reddish-purple, on strongly ascending to erect peduncle equaling or surpassing shorter petioles; seeds 1.4–1.8 × 1.0–1.2 mm, dark bronze, unspotted; known only from type area, Jacksonville, FL | |
| Viola chalcosperma Brainerd | ||
| 33b | Auricles not elongating in fruit, ca. 1 mm; cleistogamous capsule heavily purple-spotted or -blotched, on short initially prostrate peduncle much shorter than petioles and arching upward just prior to dehiscence; seeds 1.7–2.4 × 1.3–1.7 mm, light brown with prominent brown streaks or blotches; FL and Gulf Coastal Plain | |
| Viola “Gulf Coastal Plain edulis” | ||
| 34a (2) | At least some petioles prominently winged throughout much or all of their length; lowest sepals linear-lanceolate, acuminate (ovate-triangular, acute to obtuse in V. villosa); auricles prominent, elongating in fruit, erose (auricles short and entire, remaining < 1 mm in fruit in Viola patrinii); cleistogamous capsule unspotted, on declined or erect peduncle; in dry acidic sandy or gravelly soils (sandy loam soils in V. villosa) of oak or oak-pine forests, barrens and forest borders (sidewalk cracks or mulch of gardens in Viola patrinii) | 35 |
| 34b | Petioles not prominently winged; lowest sepals lanceolate to (more commonly) ovate-lanceolate, oblong or ovate, acuminate to rounded; auricles inconspicuous and remaining short and rounded, or prominent and elongating in fruit and often erose; cleistogamous capsule unspotted or spotted, on prostrate, declined or erect peduncle; in diverse substrates and habitats | 38 |
| 35a (34) | Petioles, lower surface of leaf blades and peduncles moderately to densely hirtellous (rarely glabrous in V. fimbriatula); at least the outer leaves widely spreading or prostrate on the substrate in life; largest leaf blades elliptical or narrowly oblong-ovate in outline; peduncle hirtellous; calyx ciliate; corolla purple, petals broadly rounded, spurred petal not medially compressed; peduncle of cleistogamous capsule declined; seeds 1.4–1.9 × 0.9–1.3 mm, medium to dark brown or gray-brown, unspotted or with small weak darker blotches | 36 |
| 35b | Foliage glabrous or surfaces of leaf blades sparsely appressed-hirsute near margins; leaves ascending to erect in life; petioles > 2 × as long as leaf blades (shorter in long-leaved Viola patrinii); largest leaf blades narrowly oblong- or ovate-triangular, triangular or deltate-triangular; peduncle glabrous; calyx eciliate; corolla violet, petals commonly emarginate, spurred petal commonly medially compressed (petals rounded and spurred petal not medially compressed in Viola emarginata [Lower Midwest variant], and in Viola patrinii with white or scarcely violet-tinged corolla); peduncle of cleistogamous capsule erect; seeds 1.4–2.2 × 0.9–1.5 mm, pinkish-gray to dark gray with prominent darker streaks and spots [CHECK SEEDS OF VIOLA PATRINII] | 37 |
| 36a (35) | Upper surface of leaf blades concolorous; larger leaf blades all distinctly longer than broad, elliptical or oblong to oblong-ovate (rarely lanceolate), base shallowly cordate or truncate to cuneate, apex acute; petioles shorter than leaf blades (chasmogamous flower) to 2 × as long as blades (cleistogamous fruit); lowest sepals linear-lanceolate, acuminate; upper and lateral petals of chasmogamous flower ≥ 3 mm wide; sepals of cleistogamous fruit ≥ 1/2 as long as capsule; seeds 1.3–(avg. 1.6)–1.8 × 0.9–(avg. 1.1)–1.3 mm, medium to dark brown or gray-brown with small weak or prominent darker spots, streaks or blotches | |
| Viola fimbriatula Sm. | ||
| 36b | Upper surface of leaf blades commonly bicolorous, with conspicuous darker green or purple veins; at least some larger leaf blades usually scarcely longer than broad to broader than long, narrowly ovate or orbicular to reniform (rarely elliptical), base deeply cordate, apex obtuse to narrowly or broadly rounded; petioles variable, sometimes shorter than leaf blades and sometimes > 2 × as long as blades; lowest sepals lanceolate to ovate-triangular, acute to obtuse or rounded (uncommonly acuminate); upper and lateral petals of chasmogamous flower < 3 mm wide; sepals of cleistogamous fruit < 1/2 as long as capsule; seeds 1.6–(avg. 1.9)–2.2× 1.0–(avg. 1.3)–1.5 mm, brown with minute raised black spots or dark red-brown to black and unspotted | |
| Viola villosa Walter | ||
| 37a (35) | Stipules 2/3-adnate to petiole; petiole wings broadly winged, especially in distal half; spurred petal glabrous within; spur slender and cylindrical, > 2-3 times as long as tall; lateral petal beards short, exposing throat of flower in life; auricles of cleistogamous capsule short and narrowly rounded or ovate-triangular, ≤ 1 mm long; recently reported from New York City area, NY | |
| Viola patrinii Ging. | ||
| 37b | Stipules free; petioles uniformly narrowly winged; spurred petal glabrous or bearded within; spur stout, ≤ 1.5 times as long as tall; lateral petal beards long, mostly obscuring throat of flower in life; auricles of cleistogamous capsule elongate to 3 mm or longer | 38 |
| 38a (37) | Petals commonly emarginate; spurred petal commonly medially compressed; dry sandy soils of open dry woodlands and forest edges on the Piedmont and Atlantic Coastal Plain | |
| Viola emarginata (Nutt.) Leconte [sensu stricto] | ||
| 38b | Petals broadly rounded; spurred petal not medially compressed; moist soils of lowland prairies in the Lower Midwest | |
| Viola "emarginata Lower Midwest" | ||
| 39a (34) | All petals glabrous within (lateral petals densely bearded within in V. inconspicua); spur ≥ 2 × as long as thick, cylindrical or club-shaped; stipules at least half-adnate to petioles | 39 |
| 39b | Lateral petals bearded within, spurred petal in some species bearded; spur < 1.5 × as long as thick, rounded; leaf blades variously shaped, inner edges of basal lobes not overlapping in life; stipules free | 43 |
| 40a (39) | Leaf blades narrowly ovate to ovate, base deeply cordate with inner edges of basal lobes commonly overlapping in life; upper surface of blades with scattered subappressed hairs; circumboreal, NL to AK, south to RI, PA, WI, n. MN and n. WA, disjunct in SD and CO; Greenland, Eurasia | |
| Viola selkirkii Pursh ex Goldie | ||
| 40b | Leaf blades linear-oblong or narrowly ovate-triangular to narrowly deltate-triangular, base cuneate to cordate with non-overlapping or divergent lobes; native to Asia, introduced in N America | 40 |
| 41a (40) | Spur 1–3 mm long; lateral petals densely bearded within; foliage glabrous; leaf blades narrowly deltate-triangular, base broadly cordate with divergent basal lobes, margins above basal lobes commonly concave; naturalized in FL panhandle | |
| Viola inconspicua Blume | ||
| 41b | Spur 3–8 mm long; lateral petals glabrous (rarely sparsely bearded) within; foliage puberulent (uncommonly glabrous); leaf blades linear-oblong to narrowly ovate-triangular, base cuneate to narrowly cordate with downward-pointing basal lobes, margins above base or basal lobes parallel or convex; introduced to Northeast or Great Plains | 42 |
| 42a (41) | Larger leaf blades narrowly triangular-ovate, base subcordate to shallowly cordate; spur slender; auricles 1–1.5 mm long; native to temperate Asia, sporadic waif in botanical gardens in MA and NY, naturalized in FL | |
| Viola japonica Langsd. ex DC. | ||
| 42b | Larger leaf blades linear-oblong to lanceolate or lance-triangular, base cuneate to truncate; spur stout; auricles 2–3 mm long; native to temperate and tropical Asia, introduced to lawns and roadsides near Kansas State University in Manhattan, KS, reported also from NE | |
| Viola philippica Cav. | ||
| 43a (39) | Leaves spreading to prostrate on the substrate in life; upper leaf blade surface silvery- or gray-green with contrasting dark green or red-purple veins, lower blade surface purple-tinged; foliage glabrous except for conspicuous stiff ascending or spreading hairs uniformly distributed over upper surface of leaf blade; calyx eciliate; lowest sepals oblong to ovate, obtuse to rounded; spurred pet densely bearded; cleistogamous capsule purple-spotted, on initially prostrate peduncle shorter than petioles; seeds 1.5–2.1 × 1.1–1.4 mm, light brown, commonly with slightly darker streaks and spots | |
| Viola hirsutula Brainerd | ||
| 43b | Leaves held above the substrate in life (prostrate in V. villosa, at least outer leaves prostrate especially in fruit in V. fimbriatula); upper surface of leaf blades uniformly green, lower surface green or purple tinged; foliage glabrous or variously pubescent, if hairs confined to upper surface of leaf blade, then these very small, scattered and (sub)appressed | 44 |
| 44a (43) | Margins of largest leaf blades closely pectinately serrate, surfaces glabrous or sparsely appressed-hirtellous; chasmogamous flowers held above the leaves; lowest sepals linear-lanceolate, acuminate; auricles prominent, elongating to 3 mm in fruit; sporadic along Atlantic Coastal Plain | |
| Viola pectinata E.P.Bicknell | ||
| 44b | Margins of largest leaf blades merely crenate to serrate, various in indument; chasmogamous flowers held above or among the leaves; lowest sepals and auricles various; most species absent from or rare on the Atlantic Coastal Plain | 45 |
| 45a (44) | Plant in chasmogamous flower | 45 |
| 45b | Plant in cleistogamous fruit | 67 |
| 46a (45) | Largest leaf blades approx. as broad as long to broader than long (length:width ratio < 1.2), broadly ovate or orbicular to deltate or reniform (one largest leaf blade often longer than broad in V. floridana, V. latiuscula and V. septentrionalis, which are keyed here) | 47 |
| 46b | Largest leaf blades distinctly longer than broad (length:width ratio ≥ 1.2) | 59 |
| 47a (46) | Spurred petal densely bearded within; lower surface of leaf blades commonly purple-tinged (blades uniformly green in V. retusa) | 48 |
| 47b | Spurred petal glabrous within; foliage green (foliage blue-green, petioles, midrib on upper surface of leaf blades, lower surface of leaf blades, peduncle and calyx purple-tinged in V. "sororia hirsutula-like") | 51 |
| 48a (47) | Foliage and peduncles sparsely to densely hirsute, leaf blade margins spreading-ciliate (hairs long in Appalachian populations); calyx glabrous or appressed-hirtellous, ciliate to apex (hairs long in Appalachian populations); auricles prominent, quadrate and/or erose | |
| Viola septentrionalis Greene | ||
| 48b | Foliage strictly glabrous or upper surface of leaf blades with small scattered subappressed hairs, blade margins eciliate; peduncle glabrous; calxy glabrous, eciliate; auricles short and rounded | 49 |
| 49a (48) | Largest leaf blades orbicular to reniform, broadly obtuse to rounded at apex; lowest sepals oblong to ovate, obtuse to rounded; dry or wet calcareous open sites throughout ne. North America, Great Plains and the Rocky Mountains, sporadic southward along the Appalachian Mountains. to se. WV and w. VA | |
| Viola nephrophylla Greene | ||
| 49b | Largest leaf blades deltate-triangular, acute to short-acuminate at apex; lowest sepals acuminate to acutish | 50 |
| 50a (49) | Petals broadly obovate, broadly rounded; lowest sepals > 2 mm wide, oblong-lanceolate to ovate-lanceolate, acute (occasionally obtuse); lower surface of leaf blades commonly tinged with purple; summit of petioles commonly papillate or granular; dry sandy woodland soils and dry ledges in NY, PA, VT | |
| Viola latiuscula Greene | ||
| 50b | Petals narrowly obovate, upper commonly retuse; lowest sepals < 2 mm wide, linear-lanceolate to lance-triangular, acuminate; leaves uniformly green; petioles smooth; gravel alluvium and riparian zones in the Great Plains | |
| Viola retusa Greene | 51a (47) | Lowest sepals oblong to ovate, obtuse to rounded; auricles not prominent, short and rounded or truncate | 52 |
| 51b | Lowest sepals linear-lanceolate to ovate-triangular, acuminate; auricles prominent, narrowly linear to trapezoidal | 54 |
| 52a (51) | Foliage sparsely to densely hirsute; chasmogamous and cleistogamous peduncles sparsely to moderately hirsute; calyx ciliate; widespread in e. North America westward into the e. Great Plains | |
| Viola sororia Willd. [sensu stricto] | ||
| 52b | Foliage strictly or essentially glabrous, upper surface of leaf blades in some taxa with scattered small to minute subappressed hairs (petioles sometimes sparsely hirtellous in V. "sororia hirsutula-like"); chasmogamous and cleistogamous peduncles glabrous; calyx eciliate | 53 |
| 53a (52) | Foliage, peduncles and calyx uniformly medium green; apex of leaf blades obtuse or abruptly acutish; margins incurved-serrate or closely serrulate; lowest sepals oblong to narrowly ovate (uncommonly broadly so), obtuse to rounded at apex | |
| Viola "sororia glabrous" | ||
| 53b | Foliage, peduncle and calyx blue-green, midrib of upper leaf blade surface, lower surface of leaf blades, petioles, peduncle and calyx tinged with purple; apex of leaf blades broadly rounded; margins shallowly crenate; lowest sepals ovate, broadly rounded at apex (occasionally narrowly so) | |
| Viola "sororia hirsutula-like" | ||
| 54a (51) | Corolla pale blue or violet with purple eyespot; lowest sepals linear-lanceolate; lateral petal beards very short, exposing throat in life, hairs strongly clavate to reniform | |
| Viola cucullata Aiton | ||
| 54b | Corolla violet to purple (white with broad blue, blue-gray or purple eyespot in V. communis f. priceana, white with partial purple eyespot in V. floridana “peninsular Florida”); lowest sepals lance- to ovate-triangular; lateral petal beards long, obscuring throat in life, hairs filiform or slightly clavate | 55 |
| 55a (54) | Corolla purple (white with broad blue, blue-gray or purple eyespot in V. communis f. priceana); petioles ascending in life; leaf blades suborbicular or ovate-deltate, broadly rounded to obtuse at apex, deep green, glossy on both surfaces in life; foliage strictly glabrous or upper leaf blade surface with scattered minute appressed hairs requiring magnification; auricles weakly prominent, trapezoidal, commonly erose, 1.5–2 mm; ; in moist clay or loam soils of thickets, grassy banks and meadows, slope-floodplain transitions, floodplains, lawns, roadsides and suburban woodlots, mostly absent from the Atlantic and Gulf Coastal Plains | 56 |
| 55b | Corolla white with partial purple eyespot (V. floridana “peninsular Florida”) or violet to rose-violet; petioles ascending to widely spreading in life; leaf blades ovate to broadly so, obtuse to subacute at apex, medium to dark green, neither surface glossy in life; marginal dentition incurved-serrate; upper surface of leaf blades with easily visible scattered appressed hairs; auricles short and rounded or truncate, < 1 mm; silty; lowland stream and river terraces and hammocks, FL and Gulf Coastal Plain | 56 |
| 56a (55) | Corolla violet to purple, lacking a conspicuous eyespot | |
| Viola communis Pollard f. communis | ||
| 56b | Corolla white with broad blue, blue-gray or purple eyespot | |
| Viola communis Pollard f. priceana (Pollard) H.E.Ballard, ined. | ||
| 57a (55) | Petioles ascending in life; flowers held among or slightly overtopping leaves; corolla rose-violet; local along w. Gulf Coast in LA, MS | |
| Viola floridana Brainerd [V. rosacea Brainerd] | ||
| 57b | Petioles and leaf blades widely spreading in life; flowers greatly overtopping leaves; corolla violet, or white with partial purple eyespot; e. Gulf Coast region in FL, s. AL and s. GA | 58 |
| 58a (57) | Corolla violet with white area near throat, lacking a pronounced partial purple eyespot but spurred petal with a few slender well separated purple nectarguide-lines near throat; lateral petals obovate and broadly rounded, spurred petal broadly obovate and broadly rounded to subtruncate at apex; FL, s. AL and s. GA | |
| Viola floridana Brainerd [sensu stricto] | ||
| 58b | Upper petals and distal portion of lateral and spurred petals white, with partial purple eyespot composed of dense bleeding and coalescing nectarguide-lines on proximal half of lateral and spurred petals; spurred petal obovate or rhombic-obovatel and angulate-rounded or trilobate at apex; central peninsular FL | |
| Viola floridana Brainerd “peninsular Florida” | ||
| 59a (46) | Spurred petal densely bearded within; foliage glabrous, or upper surface of leaf blades bearing small scattered subappressed hairs, or leaves sparsely to densely hirtellous or hirsute | 60 |
| 59b | Spurred petal glabrous within; foliage strictly glabrous or upper surface of leaf blades with small to minute scattered subappressed hairs | 64 |
| 60a (59) | Foliage glabrous, or upper surface of leaf blades bearing small scattered subappressed hairs, or leaves sparsely to moderately hirtellous; lowest sepals linear-lanceolate to lance-triangular, acuminate; calyx eciliate | 61 |
| 60b | Foliage sparsely to densely hirsute; lowest sepals oblong to ovate, narrowly to broadly rounded; calyx eciliate or ciliate | 63 |
| 61a (60) | Largest leaf blades narrowly elliptical, ovate-lanceolate, lance-triangular or sagittate; foliage glabrous or sparsely to moderately hirtellous; flowers overtopping leaves; auricles prominent and quadrate; in dry to moist sand of sand barrens and dry prairies, and lakeshores | |
| Viola sagittata Aiton | ||
| 61b | Largest leaf blades narrowly ovate- to deltate-triangular; foliage glabrous or upper surface of leaf blades bearing scattered small subappressed hairs; flowers held among the leaves; auricles short and rounded; in sandy, silty or muck soils of floodplains, drainages and swamps, or in gravel along riverbanks | 62 |
| 62a (61) | Largest leaf blades narrowly ovate-triangular; upper surface of leaf blades bearing scattered small subappressed hairs; upper petals broadly rounded; sandy and silty soils of floodplains and swamps, widely distributed in e. North America but absent from the Great Plains region | |
| Viola affinis Leconte | ||
| 62b | Largest leaf blades deltate-triangular or an occasional leaf narrowly ovate-triangular; leaves strictly glabrous; upper petals frequently retuse; gravelly riverbanks in the Great Plains region | |
| Viola retusa Greene | ||
| 63a (60) | Leaves and peduncles moderately to densely hirsute; margins of leaf blades with 10–(avg. 14)–21 teeth on each side, ciliate; calyx often pubescent, margins uniformly ciliate (often with long hairs) to apex; lowest sepals 2.7–3.8 mm wide, length:width ratio ≤ 2.1; w. Great Lakes region, se. MB and n. MN to c. Upper Peninsula of MI, disjunct in Crawford Co., MI and se. ON | |
| Viola grisea (Fernald) H.E.Ballard, ined. | ||
| 63b | Petioles glabrous or sparsely hirsute below middle, leaf blades and peduncles glabrous; margins of leaf blades with 10–(avg. 11)–14 teeth on each side, eciliate; calyx glabrous, eciliate; lowest sepals 1.9–2.7 mm wide, length:width ratio > 2.1; ME and NB, disjunct in e. NY | |
| Viola novae-angliae House | ||
| 64a (59) | Calyx ciliolate; lowest sepals oblong to ovate-lanceolate, obtuse to (narrowly) rounded; auricles short and rounded | |
| Viola missouriensis Greene | ||
| 64b | Calyx eciliate; lowest sepals linear-lanceolate to ovate-triangular, acuminate; auricles prominent to elongate | 65 |
| 65a (64) | Corolla pale blue or violet with purple eyespot; lowest sepals linear-lanceolate; lateral petal beards very short, with strongly clavate to reniform hairs; widely distributed over e. North America, mostly absent on the se. Atlantic Coastal Plain and the Gulf Coastal Plain | |
| Viola cucullata Aiton | ||
| 65b | Corolla violet, lacking purple eyespot but with flush of dark purple at base of lateral petals; lowest sepals lance- to ovate-triangular; lateral petal beards long, with slightly clavate hairs; s. Atlantic Coastal Plain and Gulf Coastal Plain | 66 |
| 66a (65) | Petioles and leaves widely spreading in life; foliage, peduncle and calyx green; auricles prominent, to ≤ 1.5 mm long; Gulf Coastal Plain, e. TX to w. FL panhandle | |
| Viola langloisii Greene | ||
| 66b | Petioles ascending in life; petioles, lower surface of leaf blades, peduncle and calyx commonly tinged or finely spotted with purple; auricles prominent to very elongate, 1.5–4 mm long; s. lower Atlantic Coastal Plain, se. VA s. to se. GA | |
| Viola impostor Burwell & H.E.Ballard, ined. | ||
| 67a (45) | Largest leaf blades substantially longer than broad (length:width ratio ≥ 1.2), lance-triangular or sagittate to narrowly ovate-triangular | 68 |
| 67b | Largest leaf blades about as long as broad to broader than long (length:width ratio < 1.2), ovate or deltate-triangular to reniform | 70 |
| 68a (67) | Leaf blades lance-triangular or sagittate; foliage strictly glabrous or sparsely to moderately hirtellous; peduncle glabrous; cleistogamous capsule unspotted, on erect peduncle; calyx eciliate; lowest sepals lanceolate to lance-triangular, acuminate; auricles elongating to 3 mm or more; distributed almost exclusively s. of the boreal region | |
| Viola sagittata Aiton | ||
| 68b | Leaf blades narrowly ovate-triangular; foliage glabrate or sparsely to densely hirsute; peduncle glabrous or hirsute; cleistogamous capsule heavily purple-spotted or blotched, on prostrate peduncle arching upward just prior to dehiscence; calyx eciliate or ciliate; lowest sepals oblong to ovate, narrowly to broadly rounded; auricles weakly elongating to 2 mm; confined to the boreal region | 69 |
| 69a (68) | Petioles and lower surface of leaf blades moderately to densely hirsute; peduncle hirsute; margins of leaf blades with 10–(avg. 14)–21 teeth on each side, ciliate; calyx often pubescent, margins uniformly ciliate (often with long hairs) to apex; lowest sepals 2.7–3.8 mm wide, length:width ratio ≤ 2.1; w. Great Lakes region, se. MB and n. MN to c. Upper Peninsula of MI, disjunct in Crawford Co., MI and se. ON | |
| Viola grisea (Fernald) H.E.Ballard, ined. | ||
| 69b | Petioles glabrous or sparsely hirsute below middle, leaf blades glabrous; peduncle glabrous; margins of leaf blades with 10–(avg. 11)–14 teeth on each side, eciliate; calyx glabrous, eciliate; lowest sepals 1.9–2.7 mm wide, length:width ratio > 2.1; ME and NB, disjunct in e. NY | |
| Viola novae-angliae House | ||
| 70a (67) | Petioles and lower surface of leaf blades hirsute; peduncle hirsute; calyx ciliate | 70 |
| 70b | Foliage strictly glabrous or upper surface of leaf blades with scattered small to minute subappressed hairs (petioles sometimes sparsely hirtellous in V. "sororia hirsutula-like"); peduncle glabrous; calyx eciliate (ciliolate in V. missouriensis) | 72 |
| 71a (70) | Margins of leaf blades ciliate with spreading hairs (hairs often long in Appalachian populations); sepals ciliate to apex (cilia often long in Appalachian populations); auricles prominent, quadrate and/or erose, elongate to 2 mm; seeds 1.2–2.3 × 0.8–1.2 mm, light-medium brown to dark brown, unspotted or with small weak darker streaks or spots; inhabiting limestone and dolomite-associated soils in the boreal region of n. North America and southward at higher elevations into the s. Appalachian Mountains | |
| Viola septentrionalis Greene | ||
| 71b | Margins of leaf blades ciliate with short ascending hairs; sepals ciliate in proximal 1/2(2/3) with short hairs; auricles short and rounded; seeds 1.5–2.6 × 0.9–1.6 mm, dark gray to dark grayish-brown or blackish, unspotted or with small usually weak blackish streaks; inhabiting drier to moist loamy, sandy or clayey soils in upland and lowland forests in much of e. North America | |
| Viola sororia Willd. [sensu stricto] | ||
| 72a (70) | Capsule unspotted | 73 |
| 72b | Capsule finely spotted, or heavily purple-spotted or blotched | 77 |
| 73a (72) | Peduncle declined | 74 |
| 73b | Peduncle erect (initially prostrate and coiled then elongating to become sinuous-erect in V. communis) | 75 |
| 74a (73) | Petioles and leaves widely spreading in life; leaf blades deltate-triangular, broadly acute or right-angled at apex; lowest sepals lanceolate, acuminate; auricles prominent, elongating to 2 mm; seeds yellow-brown; silt or sand in floodplains of streams and rivers in Gulf Coast region and FL | |
| Viola langloisii Greene | ||
| 74b | Petioles ascending in life; leaf blades reniform, broadly obtuse to rounded at apex; lowest sepals oblong to ovate, obtuse to rounded; auricles short and rounded; seeds 1.3–1.9 × 0.7–1.2 mm, medium brown to dark olive-brown, unspotted or rarely with minute raised darker spots; dry or wet calcareous open sites throughout ne. North America, Great Plains and the Rocky Mountains, sporadic southward along the Appalachian Mountains. to se. WV and w. VA | |
| Viola nephrophylla Greene | ||
| 75a (73) | Largest leaf blades suborbicular to deltate-reniform, apex broadly obtuse to rounded, both surfaces glossy in life; peduncle initially prostrate and coiled but eventually becoming sinuous-erect; lowest sepals ovate-triangular, < 1/2 as long as capsule; auricles weakly elongate to 2 mm; seeds 1.5–2.5 × 0.9–1.5 mm, brownish-black to blackish, with minute raised black spots or rarely unspotted; in moist clay or loam soils of thickets, grassy banks and meadows, slope-floodplain transitions, floodplains, lawns and roadside; in moist clay or loam soils of thickets, grassy banks and meadows, slope-floodplain transitions, floodplains, lawns, roadsides and suburban woodlots | |
| Viola communis Pollard | ||
| 75b | Largest leaf blades ovate, apex acute, neither surface glossy in life; peduncle erect; lowest sepals linear-lanceolate to lanceolate, > 1/2 as long as the capsule; auricles weakly or strongly elongate; seeds medium to dark brown or reddish-brown, unspotted or spotted; intermittently or permanently wet soils of wetlands, swamps and riverbanks | 76 |
| 76a (75) | Auricles strongly elongate, 3–8 mm; seeds 1.4–1.9 × 0.8–1.3 mm, dark brown to dark reddish-brown, unspotted; open or forested wet sites including marshes, sedge meadows, seeps, bog forests and swamps throughout most of e. North America, mostly e. of the Great Plains | |
| Viola cucullata Aiton | ||
| 76b | Auricles weakly elongate to 1.5 mm; seeds 1.7–2.2 × 1.0–1.3 mm, medium brown with minute raised black spots; gravel alluvium and riparian zones in the Great Plains | |
| Viola retusa Greene | ||
| 77a (72) | Lowest sepals oblong- to ovate-lanceolate or ovate, obtuse to rounded at apex | 78 |
| 77b | Lowest sepals linear-lanceolate to ovate-triangular, acuminate (acute to narrowly rounded in V. latiuscula) | 80 |
| 78a (77) | Calyx ciliolate; seeds 1.5–2.2 × 1.0–1.3 mm, medium orange-brown, unspotted or with small weak darker streaks, blotches and spots; sandy or silty soils of bottomland forests, in w. Midwest, Lower Midwest and Great Plains | |
| Viola missouriensis Greene | ||
| 78b | Calyx eciliate; seeds 1.5–2.0 × 1.0–1.3 mm [limited measurements, upper ranges may be larger], light to medium gray or gray-brown with small prominent gray or gray-brown streaks (seeds of Viola "sororia hirsutula-like" unknown); various substrates, especially in rich mesic upland forests, in the Appalachian Mountains and associated uplands | 79 |
| 79a (78) | Foliage, peduncles and calyx uniformly medium green; largest leaf bladea deltate-reniform, base cordate to subcordate (subtruncate and shortly decurrent onto petiole in V. domestica), apex obtuse or abruptly acutish; margins incurved-serrate or closely serrulate; lowest sepals oblong to narrowly ovate (uncommonly broadly so), obtuse to rounded at apex | |
| Viola "sororia glabrous” | ||
| 79b | Foliage, peduncles and calyx blue-green, midrib of upper leaf blade surface often purple, lower surface of leaf blades, petioles, peduncles and calyx tinged with purple; largest leaf blades broadly ovate to reniform, base deeply cordate, apex broadly rounded or apiculate; margins shallowly crenate; lowest sepals ovate, narrowly to broadly rounded at apex | |
| Viola "sororia hirsutula-like" | ||
| 80a (77) | Peduncle declined, or initially prostrate and coiled but becoming erect-sinuous; auricles prominent, weakly to strongly elongate, 1.5-4 mm; seeds olive-brown or brownish-black to black, unspotted or with minute black spots | 81 |
| 80b | Peduncle initially prostrate, arching upward prior to capsule dehiscence; auricles short and rounded or truncate; seeds yellow- to orange-brown or purple-black and unspotted, or light red-brown with dark brown or red-brown blotches | 82 |
| 81a (80) | Largest leaf blades broadly obtuse to rounded at apex, both surfaces glossy in life; peduncle stout, initially prostrate and coiled, elongating to become erect-sinuous prior to dehiscence; calyx green; auricles triangular-trapezoidal, weakly elongate to 1.5(2) mm; capsule finely spotted to heavily blotched with dark purple; seeds 1.5–2.5 × 0.9–1.5 mm, olive-brown, brownish-black to black, often with minute raised spots; in moist clay or loam soils of thickets, grassy banks and meadows, slope-floodplain transitions, floodplains, lawns, roadsides and suburban woodlots, widespread in e. North America, rare on the Atlantic Coastal Plain | |
| Viola communis Pollard f. communis and f. priceana (Pollard) H.E.Ballard, ined. | ||
| 81b | Largest leaf blades (abruptly) acute at apex, neither surface glossy in life; peduncle slender, declined or ascending from the beginning, gently curved; calyx purple-pigmented (rarely green); auricles narrowly linear, strongly elongate, (1.5)2–4 mm; capsule finely purple-spotted at least at base; seeds 1.3–1.8 × 0.9–1.2 mm, dark brown with white raphe, unspotted; frequently flooded sandy and silty soils along streams and rivers on the s. lower Atlantic Coastal Plain, se. VA s. to se. GA | |
| Viola impostor Burwell & H.E.Ballard, ined. | ||
| 82a (80) | Largest leaf blades ovate-triangular, deltate-triangular or deltate-reniform, shallowly cordate to subcordate at base, abruptly acute to right-angled at apex; seeds 1.4–2.0 mm long, yellow- to orange-brown or purple-black, unspotted; absent on the Gulf Coastal Plain | 83 |
| 82b | Largest leaf blades ovate to suborbicular, deeply cordate at base, broadly obtuse to rounded at apex; seeds 1.7–2.3 mm long, light red-brown with prominent dark brown or red-brown streaks or blotches; Gulf Coastal Plain | 84 |
| 83a (82) | Largest leaf blades approx. as broad as long, ovate- to deltate-triangular, 37–69 mm wide, broadly acute at apex, shallowly to moderately cordate at base; petioles smooth throughout; lowest sepals linear-lanceolate or lanceolate, acuminate, ≥ 1/2 as long as mature or dehisced cleistogamous capsule; cleistogamous capsules frequently hirtellous; seeds 1.4–2.0 mm, light to medium yellow- or orange-brown (rarely red-brown); moist to wet soils of swamps, floodplains and riverside meadows over much of e. North America e. of the Great Plains, mostly absent from the c. and s. Atlantic Coastal Plain, absent from the Gulf Coastal Plain | |
| Viola affinis Leconte | ||
| 83b | Largest leaf blades much broader than long, broadly deltate-reniform, 34–145 mm wide, abruptly obtuse to acute at apex, truncate to subcordate at base; summit of petioles granular or papillate-puberulent; lowest sepals broadly acute, mostly < 1/2 as long as mature or dehisced cleistogamous capsule; cleistogamous capsules glabrous; seeds purple-black, with very weak darker blotches, spots or streaks; dry sandy soils in upland forests or dry ledges in NY, PA, VT | |
| Viola latiuscula Greene | ||
| 84a (82) | Petioles and leaf blades widely spreading in life; seeds broadly obovoid; e. Gulf Coast region in FL, s. AL and s. GA | |
| Viola floridana Brainerd [sensu stricto and “peninsular Florida”] | ||
| 84b | Petioles ascending in life; seeds narrowly obovoid; w. Gulf Coast region in LA, MS | |
| Viola floridana Brainerd [V. rosacea Brainerd] |