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Delphinium basalticum

basalt larkspur, basaltic larkspur, Columbia Gorge larkspur

Brown's larkspur, duncecap larkspur, giant, giant larkspur, glaucous larkspur, Hooker's larkspur, mountain, mountain larkspur, or tall larkspur, pale larkspur, pale-flower Brown's larkspur, Sierra larkspur, tall larkspur, western larkspur

Stems

20-50(-65) cm;

base often reddish, puberulent.

(60-)100-200(-300) cm;

base usually green, glabrous, glaucous.

Leaves

blade round, 2-6 × 5-9 cm, not succulent, nearly glabrous; ultimate lobes 5-19, width 3-15 mm (basal), 1-12 mm (cauline).

blade round to pentagonal, 2-11 × 3-18 cm, margins seldom laciniate, glabrous; ultimate lobes 5-9(-15), width 5-24(-35) mm, tips abruptly tapered to mucronate apex;

midcauline leaf lobes more than 3 times longer than wide.

Inflorescences

(2-)6-16(-26)-flowered;

pedicel 2-7 cm, nearly glabrous;

bracteoles 4-12 mm from flowers, green, linear, 3-7 mm, nearly glabrous.

(13-)40-90(-140)-flowered;

pedicel 1-3(-5) cm, puberulent or glabrous;

bracteoles 2-6(-10) mm from flowers, green to blue, linear, 2-7 mm, puberulent or glabrous.

Flowers

sepals dark blue, nearly glabrous, lateral sepals spreading, 15-21 × 7-10 mm, spur straight to decurved, ascending 30-45° above horizontal, 14-18 mm;

lower petal blades slightly elevated, ± exposing stamens, 7-9 mm, cleft 4-5 mm;

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

sepals bluish purple to lavender, puberulent, lateral sepals forward pointing to spreading, 8-14(-21) × 3-6 mm, spurs straight, ascending to ca. 45°, 10-15(-19) mm;

lower petal blades ± covering stamens, 4-6 mm, clefts 1-3 mm;

hairs centered, mostly near base of cleft, white.

Fruits

12-17 mm, 3.5-4 times longer than wide, glabrous.

9-20 mm, 3.5-4.5 times longer than wide, glabrous to puberulent.

Seeds

± wing-margined;

seed coat cells with surfaces smooth.

wing-margined;

seed coat cells elongate but short, surfaces smooth or roughened.

2n

= 16.

Delphinium basalticum

Delphinium glaucum

Phenology Flowering spring (-early summer). Flowering summer.
Habitat Basaltic cliff faces, n and e slopes at base of cliffs Meadows, wet thickets, bogs, streamsides, open coniferous woods
Elevation 200-500 m (700-1600 ft) 0-3200 m (0-10500 ft)
Distribution
from FNA
OR; WA
[BONAP county map]
from FNA
AK; CA; CO; ID; MT; NV; OR; UT; WA; WY; AB; BC; MB; NT; SK; YT
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

Hybrids between Delphinium basalticum and D. trolliifolium are known.

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

At the sites in Manitoba and Saskatchewan, Delphinium glaucum is naturalized, not native.

Delphinium glaucum hybridizes extensively with D. barbeyi in Utah and Colorado to the extent that hybrids [D. ×occidentale (S. Watson) S. Watson] are more common in many areas than individuals of either parental stock. It occasionally hybridizes with D. distichum, D. polycladon, D. ramosum, and D. stachydeum. Hybrids with D. brachycentrum are called D. ×nutans A. Nelson.

Tremendous variation is apparent in what is here recognized as Delphinium glaucum. This is the northern expression of the complex described in the discussion under Delphinium subsect. Exaltata. Although some geographic patterns are apparent in the variation within D. glaucum, infraspecific entities are not here recognized. Apparently because of rather recent and/or incomplete genetic isolation, the degree of differentiation between these units is not such that they can be consistently recognized.

Specimens named Delphinium splendens represent plants grown in high-moisture, low-light conditions and may occur as sporadic individuals anywhere from California to Alaska. Type specimens of D. brownii Rydberg, D. canmorense Rydberg, and D. hookeri A. Nelson represent plants grown on relatively dry sites at high latitudes. Plants from dry sites at low latitudes are represented by D. bakerianum Bornmüller and D. occidentale var. reticulatum A. Nelson. Plants with lavender to white flowers are represented by type specimens of D. brownii forma pallidiflorum B. Boivin and D. cucullatum A. Nelson. Type specimens of D. alatum A. Nelson and D. glaucum var. alpinum F. L. Wynd (an invalid name) represent plants growing above or near treeline.

Delphinium glaucum may be confused with D. californicum, D. exaltatum, D. polycladon, or D. stachydeum. For distinctions from D. californicum, see discussion under that species. Absence of basal or proximal cauline leaves, generally much larger plants (greater than 1.5 m), more flowers in the inflorescence, and shorter petioles on the leaves of D. glaucum are features that serve to distinguish this species from D. polycladon. In the latter, the leaves are primarily on the proximal stem, plants often less than 1.5 m, flowers more scattered, and petioles more than twice the length of leaf blades. Features of the sepals may be used to distinguish D. glaucum (dark lavender to blue purple, usually only minutely puberulent) from D. stachydeum (bright blue, densely puberulent). Vegetative parts of D. stachydeum are also densely puberulent, while those of D. glaucum typically are glabrous.

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

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. 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
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. 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
Synonyms D. scopulorum var. glaucum, D. splendens
Name authority M. J. Warnock: Phytologia 78: 91. (1995) S. Watson: Bot. California 2: 427. (1880)
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