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Flathead larkspur, little larkspur, low larkspur, Montana larkspur

alpine larkspur, Colorado larkspur

Stems

10-40(-70) cm;

base often reddish, glabrous to puberulent.

5-25 cm;

base green, puberulent.

Leaves

blade round, 1-4 × 1.5-7 cm, glabrous to puberulent; ultimate lobes 3-19, width 1-8 mm (basal), 1-3 mm (cauline).

blade round to pentagonal, 1.5-5 × 2-5 cm, puberulent; ultimate lobes 3-15, width 2-11 mm.

Inflorescences

3-12(-22)-flowered;

pedicel 1-4(-8) cm, ± puberulent;

bracteoles 2-7(-17) mm from flowers, green, sometimes white-margined, lanceolate, 4-6(-8) mm, puberulent.

2-8-flowered;

pedicel 1-4 cm, puberulent;

bracteoles 1-3 mm from flowers, green, linear-lanceolate, 6-10 mm, puberulent.

Flowers

sepals dark blue, puberulent, lateral sepals usually spreading, 16-21 × 6-12 mm, spurs straight to gently decurved, ascending 0-40° above horizontal, 13-23 mm;

lower petal blades covering stamens, 7-12 mm, clefts 0.1-3 mm;

hairs sparse, short, mostly on inner lobes below junction of blade and claw, white or yellow.

sepals dark blue, apex rounded, puberulent, lateral sepals spreading to forward pointing, 11-14 × 5-7 mm, spurs straight except usually slightly down-curved at apex, varying from 20° above to 20° below horizontal, 8-12 mm;

lower petal blades ± covering stamens, 4-6 mm, clefts 2-4 mm;

hairs sparse, mostly near base of cleft, centered on inner lobes, white.

Fruits

(12-)16-22 mm, 4-4.5 times longer than wide, usually puberulent.

7-12 mm, 3.5-4 times longer than wide, puberulent.

Seeds

often winged;

seed coat cells with surfaces ± smooth.

unwinged;

seed coat cells elongate, surface roughened.

Delphinium bicolor

Delphinium alpestre

Phenology Flowering mid-late summer.
Habitat Exposed talus slopes on high peaks
Elevation (3400-)3800 m and above ((11200-)12500 ft and above)
Distribution
from FNA
ID; MT; ND; NE; SD; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; NM
[BONAP county map]
Discussion

Subspecies 2 (2 in the flora).

Delphinium bicolor is closely related to D. glareosum; it differs in its wider-lobed cauline leaves, shallower petal clefts, and narrower fruits.

The Gosiute consider this plant to be poisonous (D. E. Moerman 1986, subspecies not specified).

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

Of conservation concern.

Delphinium alpestre is very similar to D. ramosum, possibly divergent from that taxon only since the most recent glaciation of North America, during which ancestors of D. alpestre might have survived on peaks above the ice, while ancestors of D. ramosum survived in valleys below the ice. Since glaciation, D. ramosum apparently has migrated upslope, near but not adjoining populations of D. alpestre.

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

Key
1. Sepals (especially in fresh material) dark blue to purple; cleft in lower petals 2 mm or less; soils not derived from limestone.
subsp. bicolor
1. Sepals (especially in fresh material) bright dark blue; cleft in lower petals at least 2 mm; soils derived from limestone.
subsp. calcicola
Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Delphinium > sect. Diedropetala > subsect. Bicoloria Ranunculaceae > Delphinium > sect. Diedropetala > subsect. Exaltata
Sibling taxa
D. alabamicum, D. alpestre, D. andersonii, D. andesicola, D. antoninum, D. bakeri, D. barbeyi, D. basalticum, 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. trolliifolium, D. uliginosum, D. umbraculorum, D. variegatum, D. viridescens, D. wootonii, D. xantholeucum
D. alabamicum, 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. trolliifolium, D. uliginosum, D. umbraculorum, D. variegatum, D. viridescens, D. wootonii, D. xantholeucum
Subordinate taxa
D. bicolor subsp. bicolor, D. bicolor subsp. calcicola
Synonyms D. ramosum var. alpestre
Name authority Nuttall: J. Acad. Nat. Sci. Philadelphia 7: 10. (1834) Rydberg: Bull. Torrey Bot. Club 29: 146. (1902)
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