This herbaceous perennial plant is 1-2½' tall, consisting of basal
flowering stalks with alternate leaves. The stalks are light green and
glabrous. The basal and lower leaves are bipinnate with 6-9 leaflets,
while the upper leaves are pinnate with 3 leaflets. When the leaves are
bipinnate, they are ternately divided into 3 groups of leaflets (2
lateral groups & a terminal group); each group has 2-3
The leaflets of basal and lower leaves are 2-3" long and 1¼-2" across;
they are medium to dark green, more or less ovate in shape, serrate or
doubly serrate along their margins, and hairless or nearly so. Some
leaflets may be deeply cleft into two lobes. The leaflets of upper
leaves are smaller in size and more narrow in shape (lanceolate or
oblong-lanceolate), otherwise they are similar to the leaflets of the
preceding leaves. The petioles of basal and lower leaves are 4-12"
long, while the petioles of upper leaves are less than 4" long. These
petioles are light green and hairless; the petioles of alternate leaves
are sheathed at their bases. The petiolule (basal stalklet) of the
terminal group of leaflets is 2-3" long, while the petiolules of
the lateral groups of
leaflets are about 1" long. In each group of leaflets, the lateral
leaflets are sessile or nearly so, while the terminal leaflet has a
secondary basal stalklet that is nearly sessile to 1" long.
The stalks terminate in
compound umbels of flowers about 1½-3½" across that are flat-topped.
Each compound umbel is divided into 10-20 umbellets, while each
umbellet is divided into 10-25 flowers. The compound umbels lack floral
bracts and the umbellets lack floral bractlets. Individual flowers are
about 1/8" (3 mm.) across, consisting of 5 white petals with incurved
an inferior ovary with a pair of styles. The peduncles of the compound
umbels are 3-6" long, light green, glabrous, angular, and grooved.
The pedicels of individual flowers are about ¼" in length, light green,
and glabrous. The blooming period occurs from late spring to
mid-summer, lasting about 1 month. The flowers are replaced by
ovoid-oblongoid fruits that are ridged and somewhat flattened; they
are about 1/8" (3 mm.) long and release their seeds at maturity during
autumn. The root system is fibrous and rhizomatous. Goutweed often
forms clonal colonies from the spreading rhizomes.
The preference is partial sun to light shade, moist to mesic
conditions, and soil containing loam, clay-loam, or sandy loam. This
plant has few problems with either insects or disease organisms. It can
spread aggressively, particularly in locales with cool moist climates.
Range & Habitat:
So far, Goutweed has rarely
from cultivation and become naturalized
in Illinois. It has been found as an escaped plant in only a few
counties of NE Illinois (see Distribution
). Because of its aggressive nature, Goutweed may
become more common in the future. It was introduced into North America
from Eurasia as an ornamental plant. Habitats include deciduous
woodlands (sandy & non-sandy), shaded ravines, woodland
cemeteries, roadsides, and waste areas. Cultivated forms of Goutweed
include those with variegated and non-variegated leaves. However, wild
specimens of Goutweed almost always have non-variegated leaves.
Floral-faunal relationships for this plant
in North America are poorly understood. Müller (1873/1883) observed
miscellaneous flies, beetles, wasps, small bees, and sawflies visiting
the flowers for either nectar or pollen in Germany. Apparently the
young foliage of Goutweed is considered edible to humans as it has been
used in the Old World as a source of food and a medicinal herb.
A flower garden in Urbana, Illinois.
Like many other species in the Carrot family, Goutweed has compound
umbels of small white flowers and compound leaves. It can be identified
by the absence of floral bracts and bractlets underneath its flowers,
and by the structure and shape of its leaves. Generally, its compound
leaves have ternately arranged leaflets (divided into groups of 3),
although the leaflets within a group sometimes occur in pairs. Compared
with many other species in the Carrot family, these leaflets are
relatively large in size and relatively broad in shape when one
considers the size of the plant. Among native wildflowers, Honewort (Cryptotaenia
) is similar in appearance to Goutweed, but the
flowers of Honewort are even smaller in size and its compound
leaves have only 3 leaflets, rather than 3 groups of leaflets.