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Key to Delphinium

Ranunculaceae

Delphinium

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1
Annual; pistil 1; petals 2, connate; leaf lobes < 1.5 mm wide; [section Consolida]; [exotics].
  2
Lower bracts of the inflorescence unlobed or the single lowermost bract with 3 lobes; pistil glabrous; follicle 8-17 mm long.
  2
Lower bracts of the inflorescence (at least 2 of them) with 3 or more lobes; pistil densely pubescent; follicle 12-25 mm long.
    4
Spur < 12 mm long; upper bracteoles overlapping the flower, attached 1-4 mm below the flower
 ⇒ Delphinium hispanicum
    4
Spur > 12 mm long; upper bracteoles not overlapping the flower, attached 4-20 mm from the flower.
      5
Inflorescence with 3 or fewer branches; stems glabrous to sparsely puberulent; follicles 12-25 mm long
 ⇒ Delphinium ajacis
      5
Inflorescence with 3 or more branches; stems pubescent; follicles 10-15 mm long
 ⇒ Delphinium pubescens
1
Perennial; pistils 3 (-5); petals 4, separate; leaf lobes > 0.5 mm wide; [natives].
  6
Follicles divergent; inflorescence a raceme or divergently branched panicle, 0.5-2 (-3) dm long; flowering plants 2-9 (-13) dm tall; flowering Mar-early Jul; [section Diedropetala; subsection Grumosa].
    7
Leaves mainly in the upper 2/3 of the stem at anthesis (basal leaves absent); follicles 8-12 mm long; flowering late Jun-early Jul
 ⇒ Delphinium newtonianum
    7
Leaves mainly basal and in the lower 1/3 of the stem at anthesis (basal leaves 0-7); follicles 11-22 mm long; flowering Mar-mid-Jun.
      8
Lower stem glabrous and glaucous; sepals glabrous; stem leaves 1-3 at anthesis; sepals medium bright blue; [Ozarks of s. MO and n. AR]
 ⇒ Delphinium treleasei
      8
Lower stem pubescent; sepals puberulent; stem leaves 1-8 at anthesis; sepals deep blue, bluish purple, pink, or white; [widespread in our area, especially inland provinces and rarely Coastal Plain].
        9
Stems (4.5-) 6-9 (-13) dm tall; flowers (sepals) deep blue; lower stem pubescent; [in sunny or semi-sunny situations, apparently endemic to n. AL]
 ⇒ Delphinium alabamicum
        9
Stems 2-6 dm tall; flowers (sepals) deep bluish purple, pink, or white; lower stem glabrous or nearly so; [usually in deep shade, widespread in our area]
 ⇒ Delphinium tricorne
  6
Follicles erect; raceme > 3 dm long; flowering plants 5-20 dm tall; flowering May-Sep.
    10
Seeds wing-margined, the surfaces smooth; stem below the inflorescence glabrous; flowering plants 8-20 dm tall; flowering Jul-Sep; [section Diedropetala; subsection Exaltata]
 ⇒ Delphinium exaltatum
    10
Seeds with prominent transverse ridges; stem below the inflorescence pubescent; flowering plants 2-10 (-15) dm tall; flowering May-Jul; [section Diedropetala; subsection Virescens].
      11
Basal leaves absent at anthesis; flowers (sepals) blue to purplish (rarely white); stems (3-) 6-10 (-15) dm tall; blade of midstem leaves not distinctly 3-parted, the ultimate segments 12-25 in number, 0.5-1.5 mm wide
 ⇒ Delphinium carolinianum ssp. carolinianum
      11
Basal leaves usually present at anthesis; flowers (sepals) blue or white; stems 2-8 (-10) dm tall; blade of midstem leaves distinctly 3-7-parted (and then usually additionally divided), the ultimate segments 3-15 in number, 2-10 mm wide.
        12
Midstem leaves with 3-9 ultimate segments, each 3-10 mm wide; roots with an elongate, vertically oriented, central axis; flowers (sepals) white to blue; [sw. AR and LA west to c. and s. TX, COA, NLE, and TAM]
 ⇒ Delphinium carolinianum ssp. vimineum
        12
Midstem leaves with 5-15 ultimate segments, each 2-6 mm wide; roots horizontal, spreading in 2-8 fascicles; sepals (sepals) white; [collectively widespread, mainly inland of the Coastal Plain].
          13
Stems usually < 4.5 dm tall; [s. KY, c. and e. TN to nw. GA and n. AL]
 ⇒ Delphinium carolinianum ssp. calciphilum
          13
Stems usually 5-8 dm tall; [w. IL, e. MO, sw. AR and e. TX westwards]
 ⇒ Delphinium carolinianum ssp. virescens