Geographic range and origin: Dwarf larkspur is native to eastern and central North America. It is either unreported or absent in the remainder of North America (including Canada).
Habitat: Dwarf larkspur occurs in partially shady mesic woodlands, moist ravines and thinly wooded slopes (often rocky), thinly wooded bluffs, and partially shaded cliffs along river banks. Although, this species prefers hilly deciduous woodlands. It grows on a wide range of soils but prefers moist, rich soils with circumneutral or higher pH.
Description: Dwarf larkspur is a relatively small larkspur, but this herbaceous perennial plant reaches a mature height of ½–1½ feet tall (6-18 in), which is primarily stalk height. Flowers are typically purple to blue and, rarely, white. They are about ¾–1 inch across, and consist of 5 petal-like sepals, 4 petals, and 3 inner pistils. The leaves on this species consist of loosely clustered basal leaves with 5 lobes, and divide into 2-3 shallow secondary lobes; 4 inches long and across.
Finely cut, palmately lobed leaves and loose clusters of spurred, purople, blue, or white flowers (Delphinium tricorne) (Photo by R.W. Smith, 6/29/12)
5 purple petal-like sepals, 4 petals, and an upper sepal which forms a long nectar spur behind the flower (Delphinium tricorne) (Photo by C. Gleason, 4/15/18)
Reproduction: Dwarf larkspur is one of the earliest flowers to emerge both in the wild and in gardens, carpeting the ground under trees, then blooms in April to May. Flower stalks typically produce racemes of 6-24 blueish, purple, or white flowers, in clusters. Each flower includes both male and female parts. Individual flowers are about ¾ inches long and bilaterally symmetric, with 5 petal-like sepals and 4 spurred flowers. Flowers may be self-pollinated or pollinated by insects. Fruit is a three parted, horn-like pod about ¾ inches long (about 2 cm).
Unopened flower bud of dwarf larkspur (Delphinium tricorne) (Photo by Z. Krajcirovic, 3/23/18)
Bilaterally symmetric flowers of dwarf larkspur (Delphinium tricorne). Flowers have 5 petal-like sepals, 4 petals, and occur on a long stalk (Photo by G. Cote)
Three parted, horn-like pod of dwarf larkspur (Delphinium tricorne). (Photo by G. Cote)
Conservation status: Relatively common, widespread and abundant throughout its natural range
Cultural importance or uses: A popular ornamental landscaping flower planted for its attractive flowers, which have the shape of starmen in children's cartoons. Various larkspurs (Delphinium spp.) are often cultivated in flower gardens, but they are usually native to areas that lie west of Illinois.
References:
Hilty, J. 2017. Illinois Wildflowers. Wildflowers of Illinois in Woodlands. URL: http://www.illinoiswildflowers.info/woodland/plants/dwf_larkspur.htm (Accessed 4/24/2018)
Lady Bird Johnson Wildflower Center. 2015. Plant database. Delphinium tricorne. URL: https://www.wildflower.org/plants/result.php?id_plant=DETR (Accessed 4/24/2018)
USDA. 2018. National Resource Conservation Service. URL: https://plants.usda.gov/core/profile?symbol=DETR (Accessed 4/24/2018)