Description: This native biennial or winter
annual plant is 1-3' tall and unbranched, except for short flowering stems in
some of the upper axils of the
leaves along the central stem. The hollow central stem
is stout, light green or reddish green, with conspicuous veins along its
length. The alternate leaves are up to 10" long and 2½" across, with
deep pinnate lobes. These lobes have coarsely serrate or dentate margins.
Sometimes the lobes of a leaf are broader toward the tip than at the base. Both
the basal leaves and leaves along the stem have a ragged appearance. The
central stem and small side stems terminate in rather tight clusters of
compound flowers. A compound flower consists of 5-15 yellow ray florets,
surrounding numerous golden yellow disk florets. Each compound flower is about
½" across, and a cluster of such flowers is about 1-5" across. The
blooming period is from mid-spring to early summer, and lasts about 2 months.
There is a conspicuous floral scent that resembles the fragrance of buttercups.
The achenes have small tufts of white hairs, and are distributed by the wind.
By late summer, Butterweed dies down and becomes inconspicuous. The root system
is shallow and fibrous.
Cultivation:
The preference is full or partial sun, and wet to moist conditions. A rich,
loamy soil is preferred. This plant is easy to grow, and can volunteer in
unexpected places. During the spring, it develops very rapidly during moist
weather. This plant tolerates temporary flooding.
Range & Habitat: Butterweed occurs primarily in
the southern half of Illinois, where it is quite common, but becomes rare or
absent in the northern half of
Illinois (see
Distribution
Map). Habitats include wet to moist areas in open floodplain forests,
meadows along rivers, black soil prairies, borders of ponds and ditches, swamps
and seeps, abandoned fields and poorly maintained lawns, and soggy waste areas.
Sometimes, this plant can form sizable colonies in disturbed areas. It is more
common in wetland areas than prairies or meadows.
Faunal Associations: Primarily small bees and
various flies visit the flowers for nectar or pollen. Less common visitors
include small butterflies and skippers. The foliage is probably toxic,
containing pyrrolizidine alkaloids like other native ragworts, therefore most
herbivores probably avoid this plant. However, rabbits nibble on the leaves
occasionally during the spring.
Photographic
Location: The photographs were taken of a plant growing in the lawn
of the webmaster's apartment complex. It was one of the strays from a
neighboring wetlands area.
Comments:
This is the weediest native Senecio spp. in Illinois. It is taller and
coarser in appearance than the other native ragworts. In particular, the
central stem is stouter (resembling Yellow Rocket of the Mustard family), and
the basal leaves are longer and more ragged in appearance.