Description: This native perennial plant is about
3-6' tall and forms an erect, sparsely branched bush, although it is
herbaceous. The stout central stem and
upper side
stems are smooth, light green or reddish purple, and glaucous. The compound
leaves are trifoliate. They are usually greyish green or blue green, and
hairless. Each leaflet is ovate or oblanceolate and pointed at both ends, with
smooth margins, and about 2" long and ¾" across. The white flowers occur
in erect racemes up to 2' long and are quite showy. They are typical pea
flowers in overall structure, and about 1" long. There is no floral scent. The
blooming period occurs from late spring to mid-summer, and lasts about
1-1½ months. The flowers are replaced by large oblong seedpods, which
are also rather showy. They are about 2" long and initially green, but later
turn black. There is a stout deep taproot, and rhizomes that may form
vegetative offsets. Once established, White Wild Indigo grows very quickly
during the spring – it often towers above the surrounding plants by
blooming time. This plant is long-lived, possibly achieving a lifespan of 100
years.
Cultivation: The preference
is full sun and moist to slightly dry soil. The soil can contain significant
amounts of loam, clay, gravelly material, or sand. This plant is not fussy
about growing conditions, and is easy to grow. However, it dislikes alkaline
soil and may fail to bloom in shady conditions. Like other wild indigos, this
plant may take several years to reach blooming size. It adds nitrogen to the
soil.
Range & Habitat: White
Wild Indigo is widely distributed and occurs in almost every county of
Illinois, but it is usually uncommon (see
Distribution
Map). In a few areas that are scattered around the state, this plant is
locally common. Some local populations may be escaped cultivated plants, or the
result of restoration efforts. Habitats include moist to dry black soil
prairies, sand prairies, thickets,
edges of marshes and sandy marshes, borders of
lakes, limestone glades, and dry clay hills. White Wild Indigo is typically
found in less disturbed habitats, partly because of limited seed dispersion.
Recovery from occasional wildfires is better than most prairie
grasses.
Faunal Associations: Worker
bumblebees pollinate the flowers. The caterpillars of some skippers and
butterflies occasionally feed on the foliage, including Erynnis
baptisiae (Wild Indigo Duskywing), Achelerus lyciades (Hoary Edge),
Colias cesonia (Southern Dogface), and Colias eurythema (Orange
Sulfur). The caterpillars of the moth Dasylophus anguina (Black-Spotted
Prominent) can also be found on the foliage. Another insect, Apion
rostrum (Wild Indigo Weevil), feeds on this plant and other Baptisia
spp. The adult weevils eat both the leaves and flowers, while their grubs
stay in the pods and eat the seeds. Because White Wild Indigo is poisonous, it
is not much bothered by mammalian herbivores. If cattle, horses, or other kinds
of livestock consume sufficient quantities of this plant, they can be seriously
poisoned.
Photographic Location: The
upper photograph was taken at the Lincoln Book Bindery in Urbana, Illinois,
while the lower photograph was taken at Meadowbrook Park in Urbana,
Illinois.
Comments: This plant was
used as a dye, although it is inferior in quality to that produced by the
Indigo Plant in the Old World. This is one of the more striking plants on the
prairie. Another scientific name for this species is Baptisia
leucantha.