FNA: Violaceae vs. Viola

Distribution

Worldwide

Nearly worldwide; temperate regions; also South America; Pacific Islands (Hawaii, Philippines, Taiwan)

Discussion

Genera 23, species 1000–1100 (2 genera, 78 species in the flora).

The Violaceae is predominantly tropical with worldwide distribution. Most genera are monotypic or oligotypic and are restricted to the New World or Old World tropics (H. E. Ballard et al. 1998; G. A. Wahlert et al. 2014). Except for Viola, Hybanthus, and Rinorea, which together account for 98% of all species in the family, most genera are limited to one continent or island system (M. Feng 2005).

Violaceae has been placed in the Violales by most authors (A. Cronquist 1981; R. F. Thorne 1992; A. L. Takhtajan 1997). Based on data from cladistic analyses, it was included in the Malpighiales in 1998 (Angiosperm Phylogeny Group 1998, 2003, 2009).

The Malpighiales clade was first identified by M. W. Chase et al. (1993) in a phylogenetic analysis of nucleotide sequences from the plastid gene rbcL (K. J. Wurdack and C. C. Davis 2009). Currently, 35 families are included in Malpighiales (Angiosperm Phylogeny Group 2009). Molecular studies employing multiple gene regions have confirmed the monophyly of Malpighiales, which includes about 16,000 species (Wurdack and Davis). Relationships within Malpighiales remain poorly understood and it is the most poorly resolved large rosid clade (Wurdack and Davis).

Violaceae were previously organized into three subfamilies, Fusispermoideae, Leonioideae, and Violoideae (W. H. A. Hekking 1988; S. A. Hodges et al. 1995). Evidence confirms that Fusispermum is basal in Violaceae and belongs in the monotypic subfamily Fusispermoideae (M. Feng 2005; T. Tokuoka 2008) and Leonioideae should be subsumed in Violoideae (Feng; Feng and H. E. Ballard 2005; Tokuoka). All genera in Violaceae except Fusispermum are currently included in the subfamily Violoideae. Usually described as having an actinomorphic corolla, the calyx and corolla of Fusispermum were reported to actually be weakly zygomorphic (G. A. Wahlert et al. 2014).

W. H. A. Hekking (1988) divided subfamily Violoideae into two tribes, Violeae and Rinoreeae. Viola and Hybanthus, the only two genera in the flora area, are placed in the Violeae.

In a study of Violaceae based on plastid and nuclear DNA sequences (rbcL, atpB, matK, and 18s rDNA), T. Tokuoka (2008) found that monophyly of the family is strongly supported. A study of 39 species of Viola occurring primarily in China using chloroplast sequences trnL-trnF, psbA-trnH, rpL16, and ITS showed that “subgenus” Viola is not monophyletic (Liang G. X. and Xing F. W. 2010). Their data imply that 1) erect stems may be more primitive than stolons or rosettes, 2) species with stigmatic beaks might have been trends in sections Trigonocarpae and Adnatae, respectively.

A study of Violaceae based on plastid DNA sequences showed that most intrafamilial taxa from previous classifications of Violaceae were not supported, that previously unsuspected generic affinities were revealed, and that reliance on floral symmetry (that is, actinomorphy versus zygomorphy) alone provides misleading inferences of relationships and heterogeneous generic circumscriptions (G. A. Wahlert et al. 2014).

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

The taxonomy of Viola is often considered difficult partly because of hybridization; more than 100 named hybrids occur in the flora area. Hybrids among the blue-flowered, acaulescent species in eastern North America and among other species are well known (E. Brainerd 1924; N. H. Russell and M. Cooperrider 1955; G. L. Stebbins et al. 1963; T. S. Cooperrider 1986; L. E. McKinney 1992; H. E. Ballard 1993, 1994; A. Haines 2011).

Other factors contribute to phenotypic variation. The dimensions of leaves and stems often increase substantially between early spring and late summer (D. Klaber 1976). Stem, leaf, and flower size vary with environmental factors such as aspect, light, available soil moisture, and other edaphic conditions (Klaber; L. E. McKinney 1992).

The number of recognized taxa and the ranks attributed to taxa vary among authors (E. Brainerd 1921; N. H. Russell 1965; L. E. McKinney 1992; H. E. Ballard 1994; N. L. Gil-Ad 1997; D. B. Ward 2006).

An effort to deal with the difficulties encountered, specifically with subsect. Boreali-Americanae (W. Becker) Gil-Ad, was made by N. L. Gil-Ad (1997, 1998). Much of his species; we do not share his conclusions about some species, such as Viola hirsutula and V. subsinuata.

We do not present an infrageneric classification for Viola here. Some species complexes have been identified (for example, V. adunca, canadensis, nuttallii, palustris, and purpurea). W. Becker (1925) provided the first infrageneric classification, which was largely followed by G. K. Brizicky (1961b), a scheme largely based on style morphology. For the most part, this classification continues to be followed (T. Marcussen and T. Karlsson 2010); some of the names used to refer to species complexes (for example, Nuttallianae) were published without rank and have been incorrectly assumed to be subsections [for example, J. Clausen (1964); Marcussen and Karlsson]. Chen Y. S. et al. (2007) replaced sections with subgenera.

Branching of stems in perennial caulescent North American Viola species is uncommon and has been documented in ten species: V. adunca, V. canadensis, V. canina, V. douglasii, V. glabella, V. pedunculata, V. pinetorum, V. purpurea, V. quercetorum, and V. walteri. Branching in these species involves the development of one or more relatively short, leafy, axillary shoots on one or more stems.

The three annual species in the flora area, V. arvensis, V. bicolor, and V. tricolor, commonly branch from the base of the main stem near or at the crown and from nodes higher on the stem.

The leaves of acaulescent species develop from the rhizome. In homophyllous plants, all leaf blades are lobed from early season through late season; the depth of sinuses depends somewhat on the age of the plant. In heterophyllous plants, the earliest leaf blades are not lobed; later-season blades are lobed. E. Brainerd (1910, 1921) placed great emphasis on these morphological distinctions to differentiate Viola taxa. Like Brainerd, L. E. McKinney (1992) found these differences to be reliable taxonomic characters.

Here, the distal portion of the style is called the style head. The shape, size, position of the stigmatic surface, and degree of bearding vary among species. Differences among style heads have been used in Viola classification (W. Becker 1925; J. Clausen 1929) and in keys. Here, we report whether the style head is bearded or beardless based on reports in the literature and our observations. Of the 30 acaulescent species in the flora area, one has a bearded style; of the 43 caulescent species, 35 are always bearded, three are bearded or beardless, and five are always beardless.

Of the 73 species of Viola in the flora area, 60 are known to produce cleistogamous flowers, nine do not, and the condition in four is unknown. In some species of acaulescent A. Mayers and E. Lord (1983, 1983b) reported that pollen grains in cleistogamous flowers of V. odorata germinate in the undehisced anther sacs; the pollen tubes then penetrate the sac and grow towards the stigma. In other groups, observations suggest that pollen is released in proximity to the recurved style (T. Marcussen and T. Karlsson 2010).

Substantial research has been conducted on Viola pollination including cleistogamous flowers (A. J. Beattie 1969, 1969b, 1971, 1972, 1974, 1976, 1978; Beattie and D. C. Culver 1979; A. C. Cortés-Palomec and H. E. Ballard 2006; T. M. Culley 2000, 2002; G. Davidse 1976; L. Freitas and M. Sazima 2003; C. M. Herrera 1990; A. Mayers and E. Lord 1983, 1983b). Pollinator rewards available in most Viola flowers include nectar and pollen.

Pollinators of violets include bumblebees, honeybees, solitary bees, syrphid flies, butterflies, skippers, hawkmoths, moths, and beeflies. Thrips have been reported in Viola flowers (M. S. Baker 1935) and while these insects are often observed with pollen attached to their bodies, there is currently no evidence they play a role in pollination of Viola. Due to the high frequency that thrips, aphids, and other minute insects with pollen on their bodies have been observed in Viola flowers, it seems probable that these insects sometimes effect pollination.

The three valves of Viola capsules usually are thick in perennial species and thin in annual species. The capsules of at least some species open relatively slowly, exposing the seeds. As the valves dry, they contract and squeeze the seeds causing them to be ejected (R. J. Little and G. Leiper 2012). Capsules that disperse seeds ballistically are usually on erect peduncles; capsules that passively release their seeds usually point downward (A. J. Beattie and N. Lyons 1975).

Most Viola seeds possess an outgrowth (elaiosome), or food body, of variable size that is often attractive to ants. S. Lengyel et al. (2010) estimated that over 70% of Violaceae species are myrmecochorous. Studies have been conducted on various aspects of myrmecochory in Viola (A. J. Beattie and N. Lyons 1975; R. Y. Berg 1975; D. C. Culver and Beattie 1978, 1980; Beattie and Culver 1981; G. Matlack 1994).

Violets of horticultural importance include Viola arvensis (field or wild pansy), V. odorata (English or sweet violet), V. tricolor (Johnny-jump-up), and V. ×wittrockiana Gams ex Nauenburg & Buttler (garden pansy). Over 120 species of Viola are grown as ornamentals (L. Watson and M. J. Dallwitz, http://delta-intkey.com).

E. Brainerd (1908) reported that Viola chinensis G. Don (= V. patrinii de Candolle ex Gingins) was established at the New York Botanical Garden, at a residence in the District of Columbia, and in his garden in Massachusetts. It appears not to have persisted; it was not mentioned by N. Taylor (1915). A. Haines (2011) noted that reports of V. chinensis in New England were based on misidentifications of V. japonica.

Native Americans in the United States and Canada used Viola species for drugs, dyes, and food (D. E. Moerman 1998). Medicinal uses included pain relief and treatment of ailments including colds and coughs and for dermatological, gastrointestinal, eye, heart, and respiratory problems. Leaves and stems of some species were used as vegetables, usually cooked. Some tribes are reported to have soaked the seeds of corn in an infusion of violet roots before planting to repel insects.

Mature plants are often needed for identification of violets. In preparing specimens of violets, care should be taken to record data on petal and spur colors, and presence and distribution of beards on lateral and other petals, or note if lacking.

Measurements of the lowest petal in the descriptions here include the spur.

When this treatment was being finalized, Viola calcicola R. A. McCauley and H. E. Ballard was described as new. Time constraints prevented it from being incorporated. Viola calcicola is acaulescent, heterophyllous, has short, vertical rhizomes, nearly white to purple corollas, and occurs only on limestone substrates. It is endemic to the Guadalupe Mountains of Texas and New Mexico.

Species 400–600 (73 in the flora).

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

Key

1. Plants caulescent; sepals not auriculate; upper 2 and lateral 2 petals not showy, 0.5–5 mm; lowest petal showy, narrowed at middle; stamens connate, lowest 2 filaments not spurred with nectary; seeds (3–)6–9.	Hybanthus
1. Plants caulescent or acaulescent; sepals auriculate; upper 2 and lateral 2 petals showy, 5+ mm; lowest petal showy, not narrowed at middle; stamens connivent, but distinct, lower 2 filaments spurred with nectary that protrudes into petal spur; seeds 6–75.	Viola

1. Plants acaulescent	→ 2
1. Plants caulescent	→ 34
2. Style head bearded; Arizona.	V. umbraticola
2. Style head beardless; not confined to Arizona	→ 3
3. Petals deep lemon-yellow.	V. rotundifolia
3. Petals not lemon yellow	→ 4
4. Leaf blades lobed	→ 5
4. Leaf blades unlobed (mid-season incised or lobed at base only in V. sagittata)	→ 13
5. Leaf blades lobes similar in width and shape	→ 6
5. Middle and lateral blade lobes differ in width and/or shape	→ 7
6. All petals beardless; cleistogamous flowers absent.	V. pedata
6. Lateral petals bearded, lowest sometimes bearded; cleistogamous flowers present.	V. pedatifida
7. Mid-season leaf blades incised or lobed at base only.	V. sagittata
7. Mid-season leaf blades incised or lobed throughout	→ 8
8. Earliest leaf blades lobed (plants homophyllous), similar to mid-season blades	→ 9
8. Earliest leaf blades unlobed, or sometimes 3-lobed (plants heterophyllous), mid-season blades lobed	→ 10
9. Middle lobes of leaf blades lanceolate or spatulate to narrowly obovate; plants usually glabrous; sepal auricles 2–3 mm.	V. brittoniana
9. Middle lobes of leaf blades narrowly deltate to narrowly elliptic; plants usually pubescent; sepal auricles 1–2 mm.	V. subsinuata
10. Mid-season leaf blades with 3–5 primary lobes, middle lobe elliptic, ovate, to widely ovate.	V. palmata
10. Mid-season leaf blades with 5–9 primary lobes, middle lobe lanceolate, spatulate, to narrowly ovate	→ 11
11. Petioles, leaf surfaces, and peduncles rarely glabrous.	V. palmata
11. Petioles, leaf surfaces, and peduncles rarely pubescent	→ 12
12. Earliest leaf blades ± deltate or 3-lobed; lowest petal 10–15 mm; plants of limestone glades and barrens.	V. egglestonii
12. Earliest leaf blades ± ovate, sometimes 3-lobed; lowest petal 15–25 mm; plants of sandy, dry or seasonally wet pine or mixed pine-deciduous woods.	V. septemloba
13. Lowest petal spur 3–10 mm	→ 14
13. Lowest petal spur 1–3 mm	→ 17
14. Capsules puberulent.	V. odorata
15. Petioles not winged.	V. selkirkii
15. Petioles narrowly winged distally	→ 16
16. Leaf base cordate.	V. japonica
16. Leaf base usually truncate, sometimes ± cordate or broadly cuneate.	V. prionantha
17. Leaf blades lanceolate, narrowly elliptic, linear, or ovate	→ 18
17. Leaf blades ovate to broadly ovate, reniform, orbiculate, elliptic, or deltate	→ 19
18. Leaf blades lanceolate or narrowly elliptic to nearly linear.	V. lanceolata
18. Leaf blades elliptic to narrowly or broadly ovate.	V. primulifolia
19. Plants stoloniferous	→ 20
19. Plants not stoloniferous	→ 23
20. Petals white	→ 21
20. Petals lilac, pale blue, violet, or deep purple, sometimes nearly white	→ 22
21. Lateral petals usually beardless; leaf blade margins serrate, ciliate or eciliate.	V. blanda
21. Lateral petals usually bearded, rarely beardless; leaf blade margins ± entire or shallowly crenate, eciliate.	V. macloskeyi
22. Bracteoles usually above middle of peduncle in chasmogamous flowers; leaf blade margins crenate, denticulate, or entire, ciliate or eciliate.	V. epipsila
22. Bracteoles usually below middle of peduncle; leaf blade margins crenulate, eciliate.	V. palustris
23. All petals beardless	→ 24
23. Lateral 2 and sometimes also lowest petals bearded	→ 25
24. Petals light violet on both surfaces; leaf blades ± deltate.	V. clauseniana
24. Petals white on both surfaces; leaf blades reniform or ovate to broadly ovate or orbiculate.	V. renifolia
25. Petals white.	V. renifolia
25. Petals violet, light to dark blue-violet, lavender-violet, light to deep or dull reddish violet, dark purple-violet or reddish purple, or deep bluish violet, rarely white	→ 26
26. Sepal auricles 2–6 mm	→ 27
26. Sepal auricles 1–2 mm	→ 28
27. Leaf blade base reniform to cordate; plants of mesic to wet habitats.	V. cucullata
27. Leaf blade base truncate, slightly sagittate or hastate, or ± cordate; plants of dry, sandy, open woods and thickets.	V. sagittata
28. Adaxial leaf surface with silvery strigose patches.	V. hirsutula
28. Adaxial leaf surface without silvery strigose patches	→ 29
29. Petioles densely pubescent	→ 30
29. Petioles glabrous or pubescent	→ 31
30. Leaf blades narrowly ovate to narrowly deltate; plants of wet, rocky shores of lakes and streams, meadows.	V. novae-angliae
30. Leaf blades elliptic, ovate, or reniform; plants of sandy pine-oak or pine-oak-hickory woods and disturbed ground.	V. villosa
31. Leaf blades ovate, broadly ovate, or reniform to broadly reniform or orbiculate	→ 32
31. Leaf blades narrowly ovate or narrowly deltate to broadly deltate	→ 33
32. Leaf blades somewhat fleshy, surfaces usually glabrous, grayish green or purplish green abaxially; plants of wet habitats in saturated soil; plants 5–15 cm.	V. nephrophylla
32. Leaf blades not fleshy, surfaces usually pubescent, green abaxially; plants of dry or mesic habitats, not in saturated soil; plants 5–50 cm.	V. sororia
33. Leaf blades sparsely pubescent, rarely glabrous adaxially; lower petal obviously bearded, rarely beardless.	V. affinis
33. Leaf blades glabrous, rarely pubescent; lower petal beardless, rarely lightly bearded.	V. missouriensis
34. Cauline stipules palmately lobed or pinnatifid, equaling leaf blade	→ 35
34. Cauline stipules unlobed, shorter than leaf blade	→ 37
35. Lateral petals ± equaling or shorter than sepals.	V. arvensis
35. Lateral petals longer than sepals	→ 36
36. Sepal auricles 0.5–2 mm; style head bearded; cleistogamous flowers axillary.	V. bicolor
36. Sepal auricles 2–4 mm; style head beardless; cleistogamous flowers absent.	V. tricolor
37. Leaves compound	→ 38
37. Leaves simple	→ 42
38. Upper 2 and lower 3 petals light golden- to deep lemon-yellow	→ 39
38. Upper 2 petals dark reddish violet, lower 3 lilac, pale yellow, or cream, seldom white	→ 40
39. Leaf blades ovate, lobes 1–2.5(–5) mm wide; cleistogamous flowers absent; capsules glabrous.	V. douglasii
39. Leaf blades reniform or ovate to ± orbiculate, lobes 2–10 mm wide; cleistogamous flowers axillary; capsules glabrous or puberulent.	V. sheltonii
40. Lower 3 petals pale yellow, cream, or ± white.	V. hallii
40. Lower 3 petals lilac, rarely white	→ 41
41. Abaxial leaf surface without distinct vein parallel to each margin, margins usually ciliate, surfaces usually puberulent; California, Idaho, Nevada, Oregon, Utah	V. beckwithii
41. Abaxial leaf surface usually with distinct vein parallel to each margin, margins eciliate, surfaces glabrous; Oregon, Washington.	V. trinervata
42. Plants stoloniferous; stems prostrate, spreading	→ 43
42. Plants not stoloniferous; stems erect, ascending, spreading, decumbent, or prostrate (sometimes later reclining to nearly prostrate in V. adunca, V. howellii)	→ 44
43. Petals lemon-yellow; cauline stipule margins entire or sparingly toothed.	V. sempervirens
43. Petals pale to bluish violet; cauline stipule margins laciniate.	V. walteri
44. Petals white or cream adaxially	→ 45
44. Petals not white or cream adaxially (sometimes almost white in V. frank-smithii; rarely white in V. adunca and V. labradorica)	→ 48
45. Basal leaf blades orbiculate-ovate to deltate, usually shiny, leathery, base cuneate; cauline blade base cuneate	V. cuneata
45. Basal leaf blades ovate to reniform or deltate, not shiny or leathery, base cordate, subcordate, rounded, hastate, attenuate (oblique or not), or truncate; cauline blade base cordate to truncate	→ 46
46. Petals white or cream on both surfaces, without yellow patch basally, spur white, 3–6 mm.	V. striata
46. Petals white on adaxial surface, with yellow patch basally, spur white, yellow, or greenish, 1–2.5 mm	→ 47
47. Spurs white, upper 2 petals, sometimes lower 3, usually tinged soft reddish violet, rarely white abaxially.	V. canadensis
47. Spurs yellow or greenish, upper 2 petals, sometimes lower 3, deep reddish violet abaxially.	V. ocellata
48. Petals blue to gray, violet to pale or soft blue-violet, pale to deep lavender-violet, soft reddish violet, or ± white adaxially	→ 49
48. Petals yellow adaxially	→ 58
49. All petals yellow basally	→ 50
49. All or just 3 lower petals white basally	→ 51
50. Leaf blades broadly reniform to ovate, base cordate; petals soft reddish violet; lowest petal 10–15 mm, spur yellow; Washington.	V. flettii
50. Leaf blades broadly ovate, deltate, or broadly deltate, base cordate to truncate; petals blue to pale violet; lowest petal 5.5–11 mm, spur white to pale violet; Nevada, Utah.	V. lithion
51. Spurs 10–20 mm; petals beardless; style head beardless.	V. rostrata
51. Spurs 1.6–8 mm; lateral petals sparsely to densely bearded; style head bearded or beardless	→ 52
52. Lateral and upper 2 petals pale purple or almost white adaxially, violet abaxially; Utah.	V. frank-smithii
52. Lateral and upper 2 petals similar color on both surfaces; not limited to Utah	→ 53
53. Basal leaves absent.	V. canina
53. Basal leaves present	→ 54
54. Spurs 2–5 mm, tip straight	→ 55
54. Spurs 3–8 mm, tip straight, curved, or pointed, hooked	→ 56
55. Sepal margins ciliate or eciliate; style head bearded; seeds light brown.	V. howellii
55. Sepal margins eciliate; style head usually beardless, sometimes bearded; seeds dark olive to ± black.	V. langsdorffii
56. Sepal auricles enlarged in fruit.	V. riviniana
56. Sepal auricles not enlarged in fruit	→ 57
57. Leaf blades usually decurrent on petiole; cauline stipule margins lacerate to laciniate.	V. adunca
57. Leaf blades not decurrent on petiole; cauline stipule margins ± entire or laciniate.	V. labradorica
58. Stems leafless proximally, leafy distally; style head bearded	→ 59
58. Stems leafy proximally and distally; style head bearded or beardless	→ 63
59. Cauline leaf blades widely or narrowly hastate to ovate, unlobed, usually mottled light green adaxially.	V. hastata
59. Cauline leaf blades ovate, reniform, deltate, rhombic, ovate-orbiculate, or reniform-cordate, unlobed or 3–12-lobed, if deltate, not mottled light green adaxially	→ 60
60. Petals lemon-yellow on both surfaces; cauline blades unlobed	→ 61
60. Petals lemon-yellow adaxially, upper 2 and sometimes lateral 2 brownish purple abaxially; cauline blades unlobed or 3–12-lobed	→ 62
61. Cauline stipules ovate to oblong, margins erose or subserrate, often glandular, apex acute to acuminate; petioles 0.2–2.9 cm; blades ovate to deltate, base cordate to truncate, apex acute; Alberta, British Columbia, Alaska, California, Idaho, Montana, Oregon, Washington.	V. glabella
61. Cauline stipules ovate, margins entire or coarsely serrate or erose, apex acute; petioles 1–10 cm; blades reniform or ovate to ovate-orbiculate or deltate, base cordate, apex acute to acuminate; c (incl. Wyoming), e North America.	V. pubescens
62. Stems 1–3; basal leaves 0–2; cauline stipules sometimes ± leaflike; peduncles 2–13 cm; California, Oregon.	V. lobata
62. Stems 1(–2); basal leaves 0(–2); cauline stipules not leaflike; peduncles 1.5–4 cm; e United States.	V. tripartita
63. Basal leaves 0; style head bearded	→ 64
63. Basal leaves 1–11; style head bearded or beardless	→ 65
64. Petioles glabrous; leaf blades 1.2–2.4 cm, margins entire or with 1–3 crenations on proximal 1/2, eciliate; Texas.	V. guadalupensis
64. Petioles usually finely puberulent, sometimes glabrate; leaf blades 1–5.5 cm, margins crenate to serrate, ciliate; California.	V. pedunculata
65. Style head beardless.	V. biflora
65. Style head bearded	→ 66
66. Cleistogamous flowers absent.	V. tomentosa
66. Cleistogamous flowers present	→ 67
67. Capsules puberulent	→ 68
67. Capsules glabrous or finely puberulent	→ 71
68. Basal blade with prominent whitish veins adaxially; seeds black.	V. charlestonensis
68. Basal blade without prominent whitish veins adaxially; seeds light to medium or dark brown or mottled gray and brown	→ 69
69. Capsules 8–12 mm.	V. quercetorum
69. Capsules 3.5–7 mm	→ 70
70. Cauline blades 2.8–9.6 × 0.3–1.4 cm, length 4–11 times width.	V. pinetorum
70. Cauline blades 0.9–5.2 × 0.2–2.9 cm, length 0.8–7.1 times width.	V. purpurea
71. Capsules ellipsoid to oblong	→ 72
71. Capsules spherical, subglobose, or ovoid	→ 73
72. Base of basal and cauline leaf blades cordate; upper 2 petals deep lemon-yellow abaxially.Viola orbiculata	→ 72
72. Base of basal and cauline leaf blades attenuate to ± truncate or subcordate; upper 2 petals brownish purple abaxially.	V. praemorsa
73. Basal leaf base usually truncate, sometimes attenuate.	V. vallicola
73. Basal leaf base attenuate (rarely truncate or subcordate in V. utahensis)	→ 74
74. Basal blade margins ± coarsely crenate-serrate.	V. utahensis
74. Basal blade margins entire or serrulate, sometimes with a few sharp teeth or crenulate	→ 75
75. Elaiosome not covering funiculus; basal and cauline leaf surfaces glabrous or puberulent on margins or veins.	V. bakeri
75. Elaiosome completely covering funiculus; basal and cauline leaf surfaces glabrous or puberulent.	V. nuttallii