Description: This native perennial plant is
about 1-2½' tall. The stems have scattered white hairs and there is
little branching, except for the production of long stalks for the flowers. The
leaves occur in 1 or 2 whorls along the stem, usually in groups of 2 or 3. They
are up to 5" long and across, and have long petioles with scattered white
hairs. Each major leaf is divided into 2 or 3 deep lobes, which are in turn
divided into 2 or 3 shallower lobes. Because these divisions are rather sharp,
the leaves are cleft. Furthermore, the margins are coarsely serrate or dentate.
The leaves are often light green or yellowish green in bright sunlight. From
the upper axil of each leaf, there occasionally develops a long stalk with a
single flower about ¾" across when it is fully open. This flower
consists of 5 white or greenish white sepals (looking like petals), and
numerous stamens with yellow or light brown anthers surrounding an elongated
central head that is prickly green. This central head contains numerous
achenes, and becomes larger and more elongated as the sepals fall off. It is
about ¾–1" long and up to ½" across, eventually turning into
a fluffy mass with numerous dark seeds. These seeds are eventually distributed
by the wind. The root system is rhizomatous, often producing vegetative offsets
from the mother plant. Tall Anemone produces an allelopathic substance,
protoanemonin, which inhibits seed germination and seedling growth in many
species of plants.
Cultivation: The preference is partial sun
and moist to mesic conditions. However, this plant tolerates full sun and
sometimes occurs in sunny habitats. The soil should consist of a rich loam that
retains moisture. Mature plants resist drought fairly well, and the leaves are
not often subject to foliar disease.
Range & Habitat: Tall Anemone is a fairly
common plant that occurs throughout Illinois, except for a few southern
counties (see
Distribution
Map). Habitats include moist to mesic black soil prairies, savannas, open
woodlands, thickets, and limestone glades. It usually doesn't stray far from
woodland areas.
Faunal Associations: Small bees and flower
flies visit the flowers occasionally for pollen. Bee visitors include Plasterer
bees and Halictid bees. Mammalian herbivores usually leave this plant alone
because the foliage contains a blistering agent that can irritate the mouth
parts and digestive tract.
Photographic
Location: Photographs were taken at Meadowbrook Park in Urbana,
Illinois.
Comments: This curious plant offers different
attractions at different times of the year. During early summer, white flowers
are produced, which are soon replaced by long-lasting thimble-shaped seedheads.
During the fall, these seedheads slowly distintegrate into white cottony masses
that remain attractive all winter. Tall Anemone can be easily distinguished
from Anemone canadensis (Canada Anemone) because its leaves have
conspicuous petioles, while the leaves of the latter species are sessile or
perfoliate. Distinguishing Tall Anemone from Anemone cylindrica
(Thimbleweed) is a bit trickier, but examination of the following
characteristics are helpful: 1) the former species has a shorter, more prickly
central head that is greater than 1/3" across, while the latter has a central
head that is 1/3" across or less and is at least twice as long as it is wide;
2) the larger leaves of the former species are sharply tripartite (cleft) and
have sharper dentation or serration along the margins, while the larger leaves
of the latter are more likely to be palmate and less cleft, with blunter and
fewer teeth along the margins.