Delphinium subsect. Grumosa

Roots 1-5(-9)-branched from within 1 cm of stem attachment, 2-7(-16) cm, cormlike to fascicled or fibrous, ± fleshy, ± succulent, usually brittle; buds minute. Stems 1(-2) per root, usually unbranched, elongation delayed 2-10 weeks after leaf initiation; base narrowed, tenuously attached to root; proximal internodes much shorter than those of midstem. Leaves basal and cauline, largest leaves near base of stem, others usually gradually smaller on distal portion of stem; basal petioles spreading, cauline petioles ascending; blade shape and lobing similar throughout. Inflorescences usually with 2-6 flowers per 5 cm, open, ± pyramidal, usually at least 3 times longer than wide, spurs rarely intersecting rachis; pedicel spreading, usually more than 1.5 cm, rachis to midpedicel angle more than 30°; bracts markedly smaller and fewer lobed than leaves. Fruits ± spreading. Seeds obpyramidal, 1.5-2.7 × 0.7-2 mm, ringed at proximal end, wing-margined or not; seed coats usually lacking wavy ridges, cells usually elongate (short and narrow in D. alabamicum, D. newtonianum, D. nuttallianum, and D. treleasei), smooth or roughened, cell margins straight.

Distribution

North America, possibly others in Asia.

Discussion

Species 13 or more (13 in the flora).

Delphinium subsect. Grumosa is an extremely difficult complex, with many variations in a number of morphologic traits. Two divergent views of the complex were represented in the work of D. M. Sutherland (1967), in which the species recognized were large agglomerations, and that of P. A. Rydberg (1917), in which species rank was used for some edaphic variants. The complex has been and continues to be a major source of confusion for identification of Delphinium in North America. Most of the low larkspurs in poisonous-plant literature are members of this subsection.

Selected References

None.

Lower Taxa

Delphinium alabamicum, Delphinium bakeri, Delphinium decorum, Delphinium gracilentum, Delphinium menziesii, Delphinium newtonianum, Delphinium nuttallianum, Delphinium nuttallii, Delphinium patens, Delphinium sutherlandii, Delphinium treleasei, Delphinium tricorne, Delphinium trolliifolium

Key

1	Sepals yellowish, white, or pink; if white then white in most members of the population.	> 2
1	Sepals bluish, maroon, or purple, not yellowish; if white then only as sporadic individuals in a population.	> 8
2	Flowers with no trace of pink or lavender.	> 3
2	Flowers (especially sepal spur) with some element of pink or lavender.	> 5
3	Spurs less than 12 mm; sepals spreading to erect.	Delphinium nuttallii
3	Spurs more than 11 mm; sepals widely spreading; lower petals usually yellow.	> 4
4	Stems less than 60 cm; widest leaf lobe less than 1 cm wide.	Delphinium menziesii
4	Stems more than 60 cm; widest leaf lobe more than 1 cm wide.	Delphinium menziesii
5	Stems less than 50(-70) cm; plants with sepal color similar to that of most other individuals in the population.	> 6
5	Stems more than (40-)50 cm; plants with sepal color dissimilar from that of most other individuals in the population.	> 7
6	Seeds with elongate blunt hairs on surface.	Delphinium tricorne
6	Seeds lacking elongate blunt hairs.	Delphinium nuttallianum
7	Plants in populations with red flowers.	Delphinium nudicaule
7	Plants in populations with blue flowers.	Delphinium trolliifolium
8	Sepals maroon; plants usually distinctly different individuals within populations.	> 9
8	Sepals bluish or purple; plants usually similar to other individuals in populations.	> 10
9	Stems puberulent proximally.	Delphinium nudicaule
9	Stems glabrous proximally.	Delphinium nudicaule
10	Leaves mostly borne on distal 2/3 of stems at anthesis; flowers usually more than 15 per main inflorescence axis.	> 11
10	Leaves mostly borne on proximal 1/3 of stems; flowers often fewer than 20 per main inflorescence axis.	> 17
11	Inflorescences as wide as long or nearly so.	Delphinium newtonianum
11	Inflorescences at least 2 times longer than wide.	> 12
12	Sepals light blue.	Delphinium trolliifolium
12	Sepals dark blue to bluish purple.	> 13
13	Lobes of midcauline leaves more than 6 mm wide; stems more than (40-)60 cm.	> 14
13	Lobes of midcauline leaves less than 6 mm wide; stems less than 60(-90) cm.	> 15
14	Leaf margins crenate.	Delphinium bakeri
14	Leaf margins ±incised.	Delphinium trolliifolium
15	Sepals bluish purple (±drab) and often partly fading upon drying (especially veins, giving sepals of dried specimens mottled appearance).	Delphinium nuttallii
15	Sepals dark deep blue and retaining color upon drying.	> 16
16	Lower petals white, yellowish, or tan; lower petal blade clefts no more than 1/3 blade length.	Delphinium sutherlandii
16	Lower petals blue to purple; lower petal blade clefts at least 1/3 blade length.	Delphinium nuttallianum
17	Sepals dark blue-purple (± drab), often partly fading upon drying (especially veins, giving sepals of dried specimens mottled appearance), distinctly puberulent externally, usually not reflexed; lower stem pubescent.	> 18
17	Sepals bright blue or purple (not drab blue-purple), usually retaining color upon drying, usually glabrous, often reflexed; if sepals drab blue-purple, puberulent, and not reflexed, then proximal portion of stems nearly glabrous to glabrous.	> 20
18	Seeds with swollen, blunt, hairlike protuberances; at least 2/3 of leaves in lower 1/4 of stems; stems more than (45-)60 cm.	Delphinium alabamicum
18	Seeds without swollen, blunt, hairlike protuberances; at least 1/3 of leaves above lower 1/4 of stems; stems less than 60(-85) cm.	> 19
19	Lower petal blade clefts at least 1/3 blade length.	Delphinium decorum
19	Lower petal blade clefts no more than 1/4 blade length.	Delphinium menziesii
20	Lateral sepals strongly reflexed; leaf blade with usually 5 or fewer lobes extending 3/5 distance to petiole (if more than 5, then pedicel puberulent), lobes often more than 7 mm wide.	> 21
20	Lateral sepals not reflexed or only weakly so; leaf blade with more than 5 lobes extending more than 3/5 distance to petiole, lobes less than 7 mm wide.	> 22
21	Pedicels spreading from rachis at nearly 90°; leaf lobes distinctly wedge-shaped, widest in distal 1/2.	Delphinium gracilentum
21	Pedicels spreading from rachis at usually less than 70°; leaf lobes less often wedge-shaped, widest near midpoint.	Delphinium patens
22	Cauline leaves 2 or fewer, less than 1/2 size of basal leaves; stems glaucous.	Delphinium treleasei
22	Cauline leaves 3 or more, similar in size to basal leaves; stems not glaucous.	> 23
23	Inflorescences at least 3 times longer than wide; lower petals tan or yellowish, at least 8 mm.	Delphinium sutherlandii
23	Inflorescences less than 3 times longer than wide; lower petals blue (except sometimes in white-flowered plants), 3-8(-11) mm.	> 24
24	Seeds with swollen, blunt, hairlike protuberances on surface.	Delphinium tricorne
24	Seeds without swollen, blunt, hairlike protuberances.	Delphinium nuttallianum