Description: This native perennial plant is about
½–2' tall. It consists of a loose cluster of basal leaves on long
petioles and a flowering stalk with a few alternate leaves. The basal leaves
are up to 4" long and across; they are palmately cleft into about 5 deep lobes,
which are in turn divided into 2-3 shallow secondary lobes. These leaves are
usually sparsely pubescent and they may have a few dentate teeth along the
margins. Their petioles are pubescent or hairy and rather stout. The alternate
leaves are clustered near the base of the flowering stalk and they are few in
number; their appearance is similar to the basal leaves. The flowering stalk is
erect, stout, and rather fleshy; it is whitish green or whitish red and usually
covered with fine white hairs. Less often, this stalk is glabrous. A raceme of
flowers up to 6-8" long occurs along the upper half of this stalk; each raceme
may consist of 6-24 flowers. Each flower is about ¾–1" across,
consisting of 5 petal-like sepals, 4 petals, and 3 inner pistils. The sepals
spread outward from the center of the flower and they are usually some shade of
purple or blue-violet; far less often, they are white. The upper sepal forms a
long nectar spur behind the rest of the flower; this spur angles upward and is
fairly straight. A few cobwebby hairs may occur along the nectar spur and the
posterior surface of the sepals. The upper two petals are quite small and
usually white toward the base; they extend backward in the nectar spur. The
lower two petals are quite hairy and usually purple or blue-violet like the
sepals. These small petals surround the whitish opening that leads to the
nectar spur. The pedicels are about as long as the flowers and usually
pubescent. The blooming period occurs during the late spring and lasts about 3
weeks. Each fertilized flower is replaced by three spreading follicles (a seed
capsule that splits open along one side). Each follicle is oblongoid and
angular, terminating in a short beak; it contains several chunky seeds. The
root system is tuberous and can form vegetative offsets.
Cultivation: The preference is light dappled shade
or partial sun, mesic to slightly dry conditions, and a soil that is rocky or
loamy. Vegetative growth and flowering proceed quickly during the
spring.
Range & Habitat: Dwarf
Larkspur occurs occasionally in the southern half of Illinois, while in the
upper half of the state it is uncommon or absent. Habitats include deciduous
mesic woodlands, moist ravines and
thinly wooded
slopes (often rocky), thinly wooded bluffs, and partially shaded cliffs along
river banks. This species displays a preference for hilly
woodlands.
Faunal Associations: The
flowers are pollinated by long-tongued bees primarily, including bumblebees,
Anthophorid bees, and some Miner bees. These insects suck nectar and collect
pollen. The flowers are also visited by butterflies, skippers, and Sphinx
moths, but Charles Robertson of Flowers and Insects (1929)
didn't think they were effective at pollination. He also observed the
Ruby-Throated Hummingbird visiting the flowers. The caterpillars of the moth
Heliothis phloxiphagus (Spotted Straw) eat the flowers of Delphinium
spp., while the maggots of Phytomyza delphinivora (Delphinium
Leaf-Miner Fly) tunnel through the leaves. The foliage of Dwarf Larkspur is
toxic to most mammalian herbivores.
Photographic Location: A wildflower garden at
Crystal Lake Park in Urbana, Illinois.
Comments: The attractive flowers have the shape of
the little starmen in children's cartoons. Dwarf Larkspur is shorter and blooms
earlier than other Delphinium spp. – this is an adaptation to its
woodland habitat. It is distinctive in having 3 widely spreading follicles per
flower, while other Delphinium spp. have follicles that are more or less
united at the base. There is some variation in color of the flowers, appearance
of the leaves, and hairiness of the stalks and leaves across different
populations of Dwarf Larkspur. The only other species in this genus that is
native to Illinois is Delphinium carolinianum (Tall Larkspur), which
consists of an eastern subspecies with blue-violet flowers and a western
subspecies with pale blue or white flowers (the latter is often called Prairie
Larkspur). Various Larkspurs are often cultivated in flower gardens, but they
are usually native to the Pacific Northwest, or annual species from the
Mediterranean area of Europe.