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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.


Leaf: generally deciduous. Flower: sepals ± equal, entire; petals unequal, lowest generally largest, with spur generally < 3 [20] mm, lateral 2 equal, generally spreading, upper 2 equal, erect or reflexed, overlapped or not, lateral 2 generally, others sometimes with beard of variously shaped hairs basally; cleistogamous flowers generally present, petals 0. Fruit: ovoid to oblong, hairy or not. Seed: 8–75.
± 500 species: temperate, worldwide, Hawaii, Andes. (Latin: classical name) Important orns including Viola odorata, Viola tricolor L. (Johnny-jump-up, wild pansy), Viola ×wittrockiana Gams (garden pansy).
Unabridged references: [Baker, M.S. 1949a. Studies in western violets. IV. Leafl. West. Bot. 5: 141–147; Baker, M.S. 1949b. Studies in western violets. VI; Madroño 10: 110–128; Baker, M.S. 1957. Brittonia 9: 217–230; Ballard, H.E. 1992. Systematics of Viola Section Viola in North Am north of Mexico. M.S. thesis, Central Michigan University, Mt. Pleasant, Michigan; Ballard, H.E. 1994. Violets of Michigan. Michigan Botanist 33: 131–199; Davidse, G. 1976. A study of some Intermountain violets (Viola Sect. Chamaemelanium). Madroño 23: 274–283; Fabijan et al. 1987. The taxonomy of the Viola nuttallii complex. Can. J. Bot. 65: 2562–2580; Gil-ad, N.L. 1995. Systematics and evolution of Viola L. subsection Boreali-Americanae (W. Becker) Brizicky. Ph.D. dissertation, Univ of Michigan, Ann Arbor, Michigan; Gil-ad, N.L. 1997. Systematics of Viola subsection Boreali-Americanae. Boissiera 53: 1–130; Gil-ad, N.L. 1998. The micromorphologies of seed coats and petal trichomes of the taxa of Viola subsect. Boreali-Americanae (Violaceae) and their utility in discerning orthospecies from hybrids. Brittonia 50: 91–121; Hitchcock, C.L. 1961. Vasc. Plant. Pacific NorthW. Vol. 3; McKinney, L.E. 1992. A taxonomic revision of the acaulescent blue violets (Viola) of North Am. Sida Botanical Miscellany, 7: 1–59; McKinney, L.E. and N. Russell. 2002. Violaceae of the Southeastern United States. Castanea 4: 369–379; Russell, N.H. 1965. Violets (Viola) of the central and eastern United States: an introductory survey. Sida 1: 1–113]

Key to Viola

1. Stem 0, internodes 0

2. Rhizomes thick, fleshy; plants without stolons ..... V. nephrophylla

2' Rhizomes thin, not fleshy; plants with stolons, at least in summer

3. Fruit puberulent; leaf blade crenate; stolons green, leafy ..... V. odorata

3' Fruit glabrous; leaf blade crenate to serrate; stolons pale, not leafy

4. Leaf blade lanceolate, narrowly ovate, or elliptic; petals white ..... V. primulifolia subsp. occidentalis

4' Leaf blade reniform, ovate, or round; petals white or lilac to pale blue or ± white, with purple lines

5. Leaf blade glabrous to coarsely hairy; petals white; plants in dense patches ..... V. macloskeyi

5' Leaf blade generally glabrous; petals lilac, pale blue, or ± white; plants not in dense patches ..... V. palustris

1' Stem present, internodes short or long

6. Stipules ± = leaf; annual; lateral petals = or generally < sepals ..... V. arvensis

6' Stipules << leaf; perennial herb; lateral petals >>sepals

7. Leaves compound

8. Petals of 1 color, light gold- or deep lemon-yellow; cleistogamous flowers present or 0

9. Leaf blades longer than wide; leaf segments 3–5, 1–2.5(5) mm wide; cleistogamous flowers 0; lateral 2 petals bearded with cylindric hairs ..... V. douglasii

9' Leaf blades wider than long; leaf segments 3, 2–10 mm wide; cleistogamous flowers present, exclusively or not; lateral 2 petals ± bearded or not with club-shaped hairs ..... V. sheltonii

8' Petals of 2 colors, upper dark red-violet, lower lilac, pale yellow, or cream to ± white; cleistogamous flowers 0

10. Lower 3 petals (apart from veins, spots) lilac to ± white; leaves generally puberulent (glabrous) ..... V. beckwithii

10' Lower 3 petals (apart from veins, spots) pale yellow, cream, or ± white, deep yellow to orange basally; leaves glabrous except veins, margins generally ciliate, stipules occasionally ciliate ..... V. hallii

7' Leaves simple

11. Lower stem erect, without leaves, peduncles

12. Upper 2 petals deep lemon-yellow abaxially; stem green; cauline leaf ovate to deltate, entire; moist to wet generally shady places ..... V. glabella

12' Upper 2 petals dark red-brown abaxially; stem generally purple; cauline leaf reniform, deltate, ± ovate, or diamond-shaped, deeply divided or not; generally dry shady or open places ..... V. lobata

13. Cauline leaf diamond-shaped, reniform-cordate, or generally deltate, not lobed or dissected ..... subsp. integrifolia

13' Cauline leaf ± ovate, deltate, or generally reniform, palmately lobed or deeply dissected ..... subsp. lobata

11' Lower stem prostrate to erect, with leaves, peduncles

14. Plant with stolon-like stem; leaves evergreen ..... V. sempervirens

14' Plant without stolon-like stem; leaves deciduous

15. Petals white at least adaxially, lateral with large purple spot basally above smaller yellow area

16. Leaf generally shiny, cauline leaf base wedge-shaped; plant glabrous ..... V. cuneata

16' Leaf not shiny, cauline leaf base ± cordate to truncate; plant ± glabrous to generally puberulent ..... V. ocellata

15' Petals not white

17. Petals light to deep violet, lavender, or blue-violet

18. Rhizome fleshy; style head glabrous; sepals not ciliate ..... V. langsdorffii

18' Rhizome woody; style head bearded; sepals ciliate or not

19. Leaf ovate to ovate-triangular, entire to crenate; sepals not ciliate; spur generally longer than wide, straight or tip hooked; California Floristic Province, Warner Mountains ..... V. adunca subsp. adunca

19' Leaf ovate to reniform, crenate; sepals ciliate or not; spur ± as long as wide, straight, tip not hooked; Klamath Ranges (near Joe Bar, Siskiyou Co.) ..... V. howellii

17' Petals yellow to orange

20. Petals gold-yellow, lowest 10–20 mm; basal leaf 0 per caudex; cleistogamous flower 0 ..... V. pedunculata

20' Petals deep lemon-yellow, lowest 6–16 mm; basal leaf 1–6 per caudex; cleistogamous flower present (0 in Viola tomentosa)

21. Fruit glabrous to minutely puberulent

22. Basal leaf blade base generally ± truncate ..... V. praemorsa subsp. praemorsa

22' Basal leaf blade base generally tapered, obliquely so or not

23. Leaf generally entire ..... V. bakeri

23' Leaf ± entire, ± crenate, serrate, wavy, or generally irregularly toothed ..... V. praemorsa subsp. linguifolia

21' Fruit puberulent to tomentose

24. Basal leaves entire; cleistogamous flowers 0; fruit tomentose; n-c High Sierra Nevada ..... V. tomentosa

24' Basal leaves not entire (Viola purpurea subsp. integrifolia, Viola pinetorum subsp. pinetorum occasionally entire); cleistogamous flowers present; fruit puberulent

25. Leaves canescent to tomentose

26. Basal leaves oblanceolate to obovate or generally linear to narrowly lanceolate, canescent to gray-tomentose; s High Sierra Nevada, Tehachapi Mountain Area, Western Transverse Ranges, San Bernardino Mountains ..... V. pinetorum subsp. grisea

26' Basal leaves oblong, ovate, or round, green-tomentose; East of Sierra Nevada, Mojave Desert ..... V. purpurea subsp. aurea

25' Leaves ± glabrous to puberulent

27. Stems mostly buried, not much elongated by end of season; plant 3–8.5(12) cm

28. Cauline leaves generally entire, puberulent; basal leaves ± crenate to irregularly shallowly dentate or entire, unlobed; Northwestern California, Cascade Range, n&c High Sierra Nevada ..... V. purpurea subsp. integrifolia

28' Cauline leaves coarsely crenate or dentate, ± glabrous; basal leaves coarsely serrate or generally irregularly dentate or crenate with 2–4 rounded lobes per side; High North Coast Ranges, Inner North Coast Ranges, San Gabriel Mountains, Great Basin Floristic Province, Desert Mountains (Panamint Range) ..... V. purpurea subsp. venosa

27' Stems generally not buried, generally elongated by end of season; plant 3–25(34.5) cm

29. Basal leaf bases cordate to truncate

30. Basal leaf generally gray-green, occasionally purple-tinted abaxially

31. Basal leaf with 4–5(6) prominent lobes per side; Transverse Ranges, Peninsular Ranges, East of Sierra Nevada, Mojave Desert ..... V. purpurea subsp. mohavensis (3)

31' Basal leaf without prominent lobes; Cascade Range, Sierra Nevada, Central Western California, Southwestern California, Modoc Plateau ..... V. purpurea subsp. quercetorum (2)

30' Basal leaf generally purple-tinted, occasionally gray-green abaxially

32. Cauline leaf not prominently lobed; basal petiole 1.8–8.5 cm; peduncle 4.6–6 cm; n High Sierra Nevada, Great Basin Floristic Province ..... V. purpurea subsp. dimorpha

32' Cauline leaf with 3–4(5) prominent lobes per side; basal petiole 4.5–14.5 cm; peduncle 1.7–14 cm; Transverse Ranges, Peninsular Ranges, East of Sierra Nevada, Mojave Desert ..... V. purpurea subsp. mohavensis (3)

29' Basal leaf bases tapered

33. Basal leaf generally gray-green, occasionally purple-tinted abaxially ..... V. purpurea subsp. quercetorum (2)

33' Basal leaf generally purple-tinted abaxially

34. Cauline leaf 2–10 × longer than wide

35. Cauline leaf blade 3.5–9.6 cm, serrate or dentate with 2–4 short projections per side to ± entire; Cascade Range, Sierra Nevada, Western Transverse Ranges, San Bernardino Mountains, San Jacinto Mountains ..... V. pinetorum subsp. pinetorum

35' Cauline leaf blade 1.5–4.8 cm, wavy, shallowly dentate, sharp-angled, or entire; Cascade Range, High Sierra Nevada, Western Transverse Ranges, San Bernardino Mountains, San Jacinto Mountains ..... V. purpurea subsp. mesophyta

34' Cauline leaf generally < 2 × longer than wide

36. Basal leaf with 4–5(6) prominent lobes per side, not shiny adaxially; Transverse Ranges, Peninsular Ranges, East of Sierra Nevada, Mojave Desert ..... V. purpurea subsp. mohavensis (3)

36' Basal leaf without prominent lobes, occasionally shiny adaxially; Northwestern California, Cascade Range, Sierra Nevada, Central Western California, Southwestern California, Modoc Plateau ..... V. purpurea subsp. purpurea


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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