Delphinium nuttallianum
Delphinium
dwarf, meadow, Nuttall's larkspur, or Sonne's larkspur, slim, thin-petal larkspur, two-lobe larkspur, upland larkspur
delphinium, larkspur
unbranched, 10-40(-70) cm;
base reddish, pubescence variable.
blade round, 1-6 × 2-12 cm, nearly glabrous; ultimate lobes 5-21, 5 or more extending more than 3/5 distance to petiole, width 1-7(-14) mm (basal), 0.5-6 mm (cauline), widest at middle or in proximal 1/2.
blade deeply palmately divided, round to pentagonal or reniform, margins entire or lobes apically crenate or lacerate, lobes of basal blades wider and fewer than those of cauline blades.
4-18(-48)-flowered, at least 2 times as long as wide;
pedicel 0.8-6 cm, pubescence variable;
bracteoles 3-8(-18) mm from flowers, green to blue, linear, 3-7 mm, pubescence variable.
terminal, 2-100(-more)-flowered racemes (occasionally branched, thus technically panicles), 5-40 cm or more;
bracts subtending inflorescence branches;
pedicels present or absent;
bracteoles (on pedicels) subopposite-subalternate, not forming involucre.
sepals usually bluish purple, rarely white to pink, puberulent, lateral sepals reflexed or spreading, 8-21 × 3-10 mm, spurs decurved to straight, ascending 20-60° above horizontal, 8-23 mm;
lower petal blades elevated, exposing stamens, blue to purple, except sometimes in white-flowered plants, 4-11 mm, clefts 2-5 mm;
hairs mostly on inner lobes below junction of blade and claw, white, rarely yellow.
bisexual, bilaterally symmetric;
sepals not persistent in fruit, 5;
upper sepal 1, spurred, 8-24 mm;
lateral sepals 2, ± ovate to elliptic, 8-18 mm;
lower sepals 2, similar to lateral sepals;
upper petals 2, spurred, enclosed in upper sepal, nectary inside tip of spur;
lower petals 2, plane, ± ovate, ± 2-lobed, clawed, 2-12 mm, nectary absent;
stamens 25-40;
filaments with base expanded;
staminodes absent between stamens and pistils;
pistils 3(-5), simple;
ovules 8-20 per pistil;
style present.
7-22 mm, 3.5-5 times longer than wide, glabrous to puberulent.
follicles, aggregate, sessile, ± curved-cylindric, sides prominently veined or not;
beak terminal, straight, 2-4 mm.
winged or not;
seed coat cell surfaces smooth or roughened, blunt hairs absent.
dark brown to black (often appearing white because of air in seed coat cells), rectangular to pyramidal, often ± rough surfaced.
= 8.
= 16.
Delphinium nuttallianum
Delphinium
Delphinium nuttallianum represents an extremely difficult complex, with many variations in a number of morphologic traits. The complex has been and continues to be a major source of confusion for identification of Delphinium in North America. Type specimens of D. nuttallianum represent plants growing under dry conditions in open areas. These are typically found at 1200-2000 m in sage scrub or lower montane forest. Delphinium nuttallianum may be confused with D. andersonii, D. antoninum, D. depauperatum, D. gracilentum, and two subspecies of D. patens (subsp. patens and subsp. montanum). Features that may be used to separate D. nuttallianum from the first four, are enumerated under the respective species discussions. From D. patens subsp. patens, D. nuttallianum may be distinguished by its narrower leaf lobes, larger fruits, and more compact inflorescence. The frequent presence of glandular hairs in the inflorescence of D. patens subsp. montanum, contrasted with their absence in D. nuttallianum, will separate these taxa. Dwarfed plants of D. polycladon may be confused with D. nuttallianum. The latter, however may be distinguished by its ringed seeds, and it does not have prominent buds or sigmoid pedicel.
Hybrids have been seen between Delphinium nuttallianum and D. andersonii, D. depauperatum (D. ×burkei Greene), D. distichum (D. ×diversicolor Rydberg), D. nudicaule, and D. polycladon.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Species ca. 300 (61 in the flora).
Three Eurasian species of Delphinium–D. elatum Linnaeus, D. grandiflorum Linnaeus, and D. tatsienense Franchet–have been commonly cultivated in North America. Of the nonnative taxa, only D. elatum is sporadically naturalized, as far as is known. Isolating mechanisms in Delphinium appear to be primarily ecological, geographic, and/or temporal. Where these distinctions are disrupted, introgression often exists. Hybridization occurs regularly between certain taxa, particularly in areas of disturbance (e.g., roadcuts, drainage ditches, clearcuts). The more common and easily recognized hybrids are included in the key.
Many names have been misapplied in Delphinium. The few misapplied names mentioned in discussions below refer to relatively widespread problems.
Unless otherwise noted, the key and descriptions refer to fresh material. Some features may be significantly altered by pressing; they can, however, usually be determined with a certain amount of effort and experience.
In the descriptions, "base of cleft" refers to the point where the cleft or sinus reaches most deeply into the petal blade.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Lower petal blades less than 1/5 length of lateral sepals; sepals never red or yellow. | Sect. Elatopsis |
1. Lower petal blades more than 1/5 length of lateral sepals; sepals blue, purple, white, red, or yellow. | Sect. Diedropetala |
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