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Delphinium trolliifolium

Columbian larkspur, cow-poison, poison delphinium, poison larkspur

Geyer's larkspur, poisonweed

Stems

(40-)60-120(-180) cm;

base usually reddish, glabrous to puberulent.

(15-)30-60(-80) cm;

base usually reddish, puberulent.

Leaves

blade ± pentagonal, 4-8 × 7-16 cm, margins ± incised, nearly glabrous; ultimate lobes 0-9, width 15-30 mm (basal), 5-20 mm (cauline), widest at middle or in proximal 1/2.

blade light green, ± round, 1-5 × 1-6 cm, densely pubescent; ultimate lobes 7-20, width 2-5 mm (basal), 2-4 mm (cauline), apex gradually tapering to point;

veins obscure.

Inflorescences

(5-)14-40(-75)-flowered, ± open, at least 2 times longer than wide;

pedicel 1-4(-9) cm, puberulent to glabrous;

bracteoles (2-)6-12 mm from flowers, green, linear, 5-9(-14) mm, puberulent.

6-30(-60)-flowered, ± open, cylindric;

pedicel ascending to spreading, 1-3(-4) cm, puberulent;

bracteoles 1-3 mm from flowers, green, lanceolate, 3-6 mm, puberulent.

Flowers

sepals dark blue, glabrous, lateral sepals spreading, (8-)14-21 × 5-9 mm, spurs straight or downcurved at apex, within 20° of horizontal, (10-)16-23 mm;

lower petal blades covering stamens, 5-10 mm, clefts 1.5-3 mm;

hairs sparse, mostly near junction of blade and claw, centered or on inner lobes, well dispersed, yellow.

sepals bright blue, puberulent, lateral sepals spreading, 10-18 × 4-8 mm, spurs straight to slightly downcurved, ascending 0-30°, 11-16 mm;

lower petal blades slightly elevated, ± exposing stamens, 4-8 mm, clefts 0.5-2 mm;

hairs centered, densest on inner lobes near base of cleft, white to light yellow.

Fruits

(15-)23-34 mm, 3.8-5.5 times longer than wide, glabrous.

11-15 mm, 3-3.5 times longer than wide, sparse puberulent.

Seeds

unwinged;

seed coats smooth.

unwinged;

seed coat cells with margins straight, surfaces ± roughened.

2n

= 16.

= 16.

Delphinium trolliifolium

Delphinium geyeri

Phenology Flowering spring. Flowering late spring–early summer.
Habitat Oak woods, coastal chaparral, wet woodlands Grasslands or Artemisia-Cercocarpus scrub
Elevation 30-1100 m [100-3600 ft] 1400-3000 m [4600-9800 ft]
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; MT; NE; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Delphinium trolliifolium occurs in the northern Coast Range of California, the Columbia River Valley to just east of Mt. Hood, and the Willamette Valley of Oregon upstream to Lane County. California plants differ somewhat from Oregon plants in pubescence patterns and habitat preferences. Further study may show that two entities are involved here.

Hybrids between Delphinium trolliifolium and D. decorum, D. menziesii subsp. pallidum (D. ×pavonaceum Ewan, Peacock larkspur), D. nudicaule, D. nuttallianum, and D. nuttallii are known. Delphinium trolliifolium is likely to be confused only with D. bakeri. Refer to discussion under that species for differences.

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

Apparently closely related to Delphinium stachydeum, D. geyeri is generally smaller, earlier flowering, with more finely dissected leaves and a more eastern geographic distribution.

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

Source FNA vol. 3. Treatment author: Michael J. Warnock. FNA vol. 3. Treatment author: Michael J. Warnock.
Parent taxa Ranunculaceae > Delphinium > sect. Diedropetala > subsect. Grumosa Ranunculaceae > Delphinium > sect. Diedropetala > subsect. Wislizenana
Sibling taxa
D. alabamicum, D. alpestre, D. andersonii, D. andesicola, D. antoninum, D. bakeri, D. barbeyi, D. basalticum, D. bicolor, D. brachycentrum, D. californicum, D. cardinale, D. carolinianum, D. decorum, D. depauperatum, D. distichum, D. elatum, D. exaltatum, D. geraniifolium, D. geyeri, D. glareosum, D. glaucescens, D. glaucum, D. gracilentum, D. gypsophilum, D. hansenii, D. hesperium, D. hutchinsoniae, D. inopinum, D. lineapetalum, D. luteum, D. madrense, D. menziesii, D. multiplex, D. newtonianum, D. novomexicanum, D. nudicaule, D. nuttallianum, D. nuttallii, D. parishii, D. parryi, D. patens, D. polycladon, D. purpusii, D. ramosum, D. recurvatum, D. robustum, D. sapellonis, D. scaposum, D. scopulorum, D. stachydeum, D. sutherlandii, D. treleasei, D. tricorne, D. uliginosum, D. umbraculorum, D. variegatum, D. viridescens, D. wootonii, D. xantholeucum
D. alabamicum, D. alpestre, D. andersonii, D. andesicola, D. antoninum, D. bakeri, D. barbeyi, D. basalticum, D. bicolor, D. brachycentrum, D. californicum, D. cardinale, D. carolinianum, D. decorum, D. depauperatum, D. distichum, D. elatum, D. exaltatum, D. geraniifolium, D. glareosum, D. glaucescens, D. glaucum, D. gracilentum, D. gypsophilum, D. hansenii, D. hesperium, D. hutchinsoniae, D. inopinum, D. lineapetalum, D. luteum, D. madrense, D. menziesii, D. multiplex, D. newtonianum, D. novomexicanum, D. nudicaule, D. nuttallianum, D. nuttallii, D. parishii, D. parryi, D. patens, D. polycladon, D. purpusii, D. ramosum, D. recurvatum, D. robustum, D. sapellonis, D. scaposum, D. scopulorum, D. stachydeum, D. sutherlandii, D. treleasei, D. tricorne, D. trolliifolium, D. uliginosum, D. umbraculorum, D. variegatum, D. viridescens, D. wootonii, D. xantholeucum
Name authority A. Gray: Proc. Amer. Acad. Arts 8: 375. (1872) Greene: Erythea 2: 189. (1894)
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