Description: The hairy stems of this native perennial plant are recurved or sprawl along the ground. They tiller from the base of the plant and are about 2' long. The alternate compound leaves are divided into three leaflets. Each leaflet is up to 3" long and about 1" wide, rather oblanceolate in shape, although pointed at both ends. There are numerous small white hairs, and the margins are smooth. The entire plant is grey-green in color.
The showy inflorescence is about 1' long,
and organized as a raceme that tends to droop toward the ground. The flowers
are creamy white or light yellow, about 1" long, and look like typical large
pea flowers. They bloom quite early for about 3 weeks from mid- to late spring.
These are replaced by large seedpods that are quite conspicuous. The entire
plant may detach from the base and blow around in the wind as a means of
dispersing the seeds, like a tumbleweed. The root system consists of a stout
central taproot.
Cultivation: The
preference is full sun (especially during the spring), mesic to dry conditions,
and loamy, sandy, or clayish soil. This plant is fairly easy to cultivate if a
site is sunny and well-drained, but it develops slowly, so some patience is
required. Like other wild indigos, this is a long-lived plant when conditions
suit it, but can be difficult to move once it becomes
established.
Range & Habitat:
Cream Wild Indigo occurs in scattered locations throughout Illinois, but it is
uncommon, except at high quality sites. Natural habitats include
mesic to dry black
soil prairies, sand prairies, sandy oak savannas, and dry barrens, particularly
in acidic soil. Recovery from occasional wildfires is very
good.
Faunal Associations: This
plant is pollinated primarily by queen bumblebees after they emerge from
hibernation during the spring. Worker bumblebees appear somewhat later. The
queen bees of a few other long-tongued bee species may visit this plant,
including Synhalonia speciosa (Eucerine Miner Bee sp.) and Osmia
bucephala bucephala (Mason Bee sp.). These insects usually seek nectar from
the flowers, but sometimes collect pollen. The caterpillars of some
butterflies, skippers, and moths feed on the foliage of this and other wild
indigos. This includes the butterflies Colias cesonia (Southern Dogface)
and Colias eurythema (Orange Sulfur), the skippers Achelerus lyciades
(Hoary Edge) and Erynnis baptisiae (Wild Indigo Duskywing), and the
moth Dasylophia anguina (Black-Spotted Prominent). Another insect
visitor is Apion rostrum (Wild Indigo Weevil). The adults feed on the
flowers and leaves, while the larvae feed on the seeds. Cream Wild Indigo is
not normally bothered by mammalian herbivores because the foliage is poisonous.
If livestock, such as cattle and horses, eat sufficient quantities of this
plant, as well as other wild indigos that may be present, they can be seriously
poisoned by it.
Photographic
Location: The photograph was taken at Loda Cemetery Prairie in
Iroquois County, Illinois.
Comments:
This is one of the earliest plants to bloom in the prairie, and is quite showy
and attractive. There is a less common variety of Cream Wild Indigo that has
hairless leaves.