Violets

Viola

1 Plant producing aerial stems bearing leaves and flowers.
  2 Petals yellow, or white with a yellow center; stipules entire or ragged-edged ........................... Key A
  2 Corolla wholly cream-colored, or cream with a yellow center, or blue-violet, or multicolored
    (blue or violet with orange or yellow); stipules fringed or deeply lobed ................................... Key B
1 Plant with leaf petioles and flower stalks arising separately from the base of the plant.
  3 Plant producing stolons; corolla white (or blue in Sweet Violet) ............................................... Key C
  3 Plant not producing stolons; corolla blue-violet ......................................................................... Key D

Key A – Stemmed Violets with yellow or white flowers
1 One species in Cape May area............................................................................ Downy Yellow Violet

Key B – Stemmed Violets with blue, cream, or multicolored flowers
1 Stipules foliaceous, deeply lobed (the lobes narrow, but not ciliate or fringed; leaves cuneate at base;
  plants annual, without thickish rootstock; [of weedy habitats].
  2 Petals pale blue with a cream center; petals 2× as long as the sepals ........ American Field Pansy
  2 Petals either cream with a yellow center or multicolored; petals < 2× as long as the sepals.
    3 Corolla cream with a yellow center; petals shorter than the sepals or longer by up to 2 mm .......
      ...................................................................................................................European Field Pansy
    3 Corolla multicolored (cream to orange with a yellow center, the upper petals at least partly dark
      blue); petals longer than the sepals by 2mm or more .................................................Wild Pansy
1 Stipules herbaceous, fringed or ciliate along the margin; leaves truncate or cordate at the base; plants
  perennial, with thickish rootstock; [mainly of natural habitats]; [section Viola].
  6 Petals wholly cream-colored ........................................................................................ Striped Violet
  6 Petals blue or blue-violet................................................................................. American Dog Violet

Key C – Stemless Violets with stolons and white (or rarely blue) flowers
1 Flowers generally blue (sometimes white or blue-and-white variegated); style terminating in a slender
  hook ca. 1 mm long; seed capsules slightly hairy; [introduced] .......................................Sweet Violet
1 Flowers white; style broad at the tip, in most species resembling a scoop; capsules glabrous; [native].
  2 Leaf blades < 1.5× as long as broad................................................................... Sweet White Violet
  2 Leaf blades > 1.5× as long as broad.
    3 Leaf blades lance-ovate, broadly cuneate to subtruncate at the base ... Primrose-leaved Violet
    3 Leaf blades linear to lanceolate, narrowly cuneate at the base.................... Lance-leaved Violet

Key D – Stemless Violets without stolons, with blue-violet or yellow flowers
1 Leaf blades deeply divided throughout, or lobed basally, or deeply toothed basally (beware that in
  Bird's-foot Violet the earliest 1-2 leaves may be uncut and cordate or shallowly lobed).
  2 Blades divided, lobed, or deeply toothed only on basal portion, or blades incised only in distal half.
    3 Orange stamens conspicuous and beak-like; blades incised only in distal half or only apically
     ........................................................................................................................... Bird's-foot Violet
    3 Stamens not conspicuous; blades divided, lobed, or deeply toothed only on basal portion.
      4 Blade outline oblong-lanceolate to ovate-triangular, much longer than wide.
        5 Petioles distinctly shorter than blades; blades densely pubescent, apex blunt, basal teeth
          undeveloped or with a few coarse teeth on mature leaves ................ Arrow-leaved Violet
        5 Petioles equal or longer than blades; blades hairless, apex acute; basal teeth well developed,
          very coarse to lobe-like ...................................................................... Arrow-leaved Violet
      4 Blade outline ovate to subrotund, about as wide as long.................... Palmate-leaved Violet
  2 Blades deeply divided throughout into linear or lanceolate segments (or with several narrow lateral
   segments and a broadly lanceolate central segment), blades about as broad as long, or broader.
    6 Central lobe of leaf blade mostly 1-2.5× the width of the first lateral lobes.................................
      ......................................................................................................................Northern Coast Violet
    6 Central lobe of leaf blade mostly 3-4× the width of the first lateral lobes.. Palmate-leaved Violet
1 Leaf blades merely serrate or crenate on margin; ovate to subrotund in outline.
  7 Most or all blades longer than broad, narrowly ovate to long-triangular, tapering to an acute apex.
    8 Blades and petioles moderately to densely pubescent; leaves distinctly longer than wide; dry
      habitats ........................................................................................................ Arrow-leaved Violet
    8 Blades and petioles glabrous or glabrate.
      9 Lateral petals bearded with clavate hairs; spurred petal glabrous within; wet habitats ...........
        ...................................................................................................................... Marsh Blue Violet
      9 Lateral petals with hairs of essentially uniform width; spurred petal bearded within.
        10 Leaf outline broadly triangular, not much longer than wide; basal teeth of the leaf numerous
         ............................................................................................................ Northern Coast Violet
        10 Leaf outline narrowly ovate-triangular, much longer than wide; basal teeth of the leaf few,
          very coarse............................................................................................. Arrow-leaved Violet
  7 Blades as wide as long or wider, ovate to suborbicular, apex obtuse (to acute).
    11 Lateral petals bearded with club-tipped hairs; foliage more or less hairless ..Marsh Blue Violet
    11 Lateral petals bearded with hairs of uniform width; foliage pubescent or not.
       12 Leaf blades moderately to densely pubescent on one surface or both, and on petioles.
         13 Leaf blades equally pubescent on both surfaces................................. Common Blue Violet
         13 Leaf blades much more pubescent on one surface than the other..Southern Wood Violet
       12 Leaf blades hairless, or with hairs confined to the basal lobes; petioles hairless ...............
         ............................................................................................................... Common Blue Violet