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Delphinium trolliifolium

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

Rocky Mountain larkspur

Stems

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

base usually reddish, glabrous to puberulent.

50-120 cm;

base often reddish, puberulent, midstems glabrous to subglabrous.

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 round to pentagonal, 1.5-10 × 2-16 cm, nearly glabrous; ultimate lobes 5-19, width 5-30 mm (basal), 1-10 mm (cauline).

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.

10-30-flowered, open, cylindric;

pedicel ascending to spreading, 1-3(-4.5) cm, puberulent;

bracteoles 2-7 mm from flowers, green, linear, 2-4 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 dark blue, nearly glabrous, lateral sepals forward pointing, 12-15 × 4-6 mm, spurs gently decurved, slightly ascending, 15-20 mm;

lower petal blades ± covering stamens, 5-8 mm, clefts 1-3 mm;

hairs sparse, centered, mostly below junction of blade and claw, white.

Fruits

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

16-20 mm, 4-4.5 times longer than wide, nearly glabrous.

Seeds

unwinged;

seed coats smooth.

wing-margined;

seed coat cells with margins straight, cell surfaces ± roughened.

2n

= 16.

= 16.

Delphinium trolliifolium

Delphinium scopulorum

Phenology Flowering spring. Flowering late summer–early autumn.
Habitat Oak woods, coastal chaparral, wet woodlands Riparian forests and open woodlands
Elevation 30-1100 m [100-3600 ft] 1700-2600 m [5600-8500 ft]
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; NM; Mexico (Sonora)
[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.)

Hybrids are known with Delphinium andesicola.

(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. 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. stachydeum, D. sutherlandii, D. treleasei, D. tricorne, D. trolliifolium, D. uliginosum, D. umbraculorum, D. variegatum, D. viridescens, D. wootonii, D. xantholeucum
Synonyms D. macrophyllum
Name authority A. Gray: Proc. Amer. Acad. Arts 8: 375. (1872) A. Gray: Smithsonian Contr. Knowl. 5(6): 9. (1853)
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