Description: This native perennial plant is 2-5'
tall, which occasionally branches out, and has a ferny appearance. The stems
are light green and angular. The alternate leaves are doubly compound
(bipinnate), consisting of many small
leaflets that are each less than
¼" long. They are yellowish green or medium green, and narrowly ovate in
shape. There may be scattered white hairs along the stems and around the
margins of the leaves. Small white compound flowers occur individually from the
upper axils of the upper leaves. Each compound flower is up to ½"
across, and composed of a multitude of narrow tubular florets pointing in
nearly all directions. From each floret protrudes several yellow stamens. When
fully developed, these compound flowers have a starburst appearance that is
typical of members in the Mimosa family, but they are more lumpy than
spherical. There is no floral scent. The blooming period lasts about a month
during early or mid-summer, after which clusters of brown seedpods develop
during the remainder of the summer. This plant has a central taproot, and
disperses by reseeding itself.
Cultivation: The preference is full or partial sun,
and moist to average conditions. Some drought is tolerated, but the leaflets on
the lower stems of the plant may fall off, and the buds of compound flowers may
abort and turn brown. Growth is best in fertile loam, but other kinds of soil
are tolerated. This plant fixes high amounts of nitrogen in the soil, and can
rejuvenate worn-out soil. Disease is rarely a problem.
Range & Habitat: Illinois Bundleflower occurs
primarily in NE Illinois, along the Illinois River valley, and along the
Mississippi River valley in SW Illinois, favoring loamy or sandy alluvial
soils. It is occasional in these areas, otherwise rare or absent (see
Distribution
Map). Habitats include moist to mesic black soil prairies, moist meadows
near rivers, openings in woodlands, limestone glades, and areas along levees.
It is sometimes planted in pastures to feed cattle, and is used in prairie
restorations to improve the soil. However, it recovers poorly from wildfires.
This plant favors disturbed areas.
Faunal
Associations: There is limited information available, but Eucerine
Miner bees probably visit the flowers for pollen or nectar. Syrphid flies and
Halictid bees may seek pollen, but are non-pollinating. The seeds are consumed
by various upland gamebirds, including the Ring-Necked Pheasant, Bobwhite, and
Greater Prairie Chicken. This plant is highly palatable to mammalian
herbivores, and has a high protein content. It may have trouble surviving in
areas where there is a surplus population of these animals and a shortage of
predators.
Photographic Location:
Photographs were taken at the webmaster's wildflower garden in Urbana,
Illinois.
Comments: The primary
attraction of this plant is its fern-like foliage, giving it a refined
appearance. The leaves close-up at night, and often close partially during hot,
sunny days. During the evening, they re-orient in the direction of the sun to
maximize the reception of its light. The little flowers are short-lived and not
particularly showy. Illinois Bundleflower is one of two members of the Mimosa
family that occur in prairies in Illinois. The other plant is Schrankia
uncinata (Sensitive Briar), which is a vine with pink starburst flowers and
thorns along the stems and compound leaves.