Flora of North America species comparison

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Delphinium robustum

Flathead larkspur, little larkspur, low larkspur, Montana larkspur

robust larkspur, wahatoya creek larkspur

Stems

10-40(-70) cm;

base often reddish, glabrous to puberulent.

100-200(-250) cm;

base sometimes reddish, glabrous, glaucous.

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, 7-12 × 10-20 cm, nearly glabrous; ultimate lobes 5-15, width 6-30 mm, tips gradually tapered to mucronate apex;

midcauline leaf lobes more than 3 times longer than wide.

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.

40-90(-180)-flowered;

pedicel 0.5-2 cm, puberulent;

bracteoles 4-6 mm from flowers, green to purple, linear, 5-8 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 bluish purple to pale lavender, nearly glabrous, lateral sepals ± forward pointing, 9-14 × 4-6 mm, spurs slightly decurved, 30-45° above horizontal, dark blue, 10-13 mm;

lower petal blades ± covering stamens, 5-7 mm, clefts 2-3 mm;

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

Fruits

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

13-18 mm, 3-4 times longer than wide, puberulent.

Seeds

often winged;

seed coat cells with surfaces ± smooth.

wing-margined;

seed coat cells elongate, surfaces smooth.

Delphinium robustum

Phenology

Flowering summer.

Habitat

Riparian woodlands, subalpine meadows

Elevation

2200-3000 m (7200-9800 ft)

Distribution

ID; MT; ND; NE; SD; WY; AB; BC; SK

[WildflowerSearch map]

[BONAP county map]

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 robustum is the representative of the southern Cordilleran complex from the Jemez, San Antonio, San Juan, San Pedro, and Sangre de Cristo mountains. Hybrids are known with D. sapellonis.

(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.

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. 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. 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

Name authority

Nuttall: J. Acad. Nat. Sci. Philadelphia 7: 10. (1834)

Rydberg: Bull. Torrey Bot. Club 28: 276. (1901)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America, OregonFlora

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