Description:
This perennial wildflower forms a low leafy rosette about 6-10"
across. Individual basal leaves are 3-5" long and 1-1¾" across; each
leaf is odd-pinnate with 3-6 pairs of lateral leaflets and a terminal
leaflet. There are also secondary leaflets that are inserted between
some pairs of lateral leaflets; these secondary leaflets are quite
small and poorly developed. These leaflets are oriented away from the
center of the rosette, forming an oblique angle with the rachis
(central stalk of the compound leaf).
Individual leaflets are
oblanceolate in
shape, shallowly cleft, coarsely dentate, and slightly ciliate
along their margins; they are somewhat variable and irregular. During
the growing season, the upper leaf surface is medium green and sparsely
covered with short appressed hairs, while the lower leaf surface is
light green and hairy primarily along the rachis and
major veins. Flowering stalks develop from the center of the rosette,
becoming 5-10" tall at maturity. Each stalk terminates in an umbel of 3
nodding flowers. The flowering stalks (peduncles) are reddish green to
reddish
purple, terete, and densely hairy. There is a pair of leafy bracts at
the base of each umbel that are deeply cleft with linear to
linear-oblong segments. These bracts are reddish green to reddish
purple
and hairy. Sometimes pairs of leafy bractlets develop along the
hairy pedicels of the flowers; these bractlets are also deeply cleft
with linear segments. Individual
flowers are ½-1" long and
similarly across. Each flower consists of 5 pale red to purplish red
sepals, 5 white to pale red petals, a central cluster of pistils, and
numerous stamens that are arranged in a ring. The sepals extend along
the entire length of the flower and they are joined together at the
base; each sepal is deltate in shape and hairy. Each flower also has 5
linear floral bracts (one floral bract between each adjacent pair of
sepals). These floral bracts
are the same color as the sepals and
hairy; they extend outward from the sepals. The
petals are largely hidden by the long sepals as the flower barely
opens. The
blooming period can occur from early to late spring and lasts about 1-2
months. Afterwards, each flower becomes erect and develops a dense
cluster of achenes with long feathery tails. These achenes are
distributed by the wind. The root system is fibrous and rhizomatous.
This wildflower can form small clonal colonies of plants from the
rhizomes. A rosette of low basal leaves persists through the winter;
these winter leaves are often reddish purple.
Cultivation:
The
preference is full sun, mesic to dry conditions, and a barren soil that
is rocky, gravelly, or sandy. Young plants should be kept well-watered
during hot summer weather as Prairie Smoke is adapted to a somewhat
cool northern climate. Competition from taller and more aggressive
plants is not tolerated.
Range
& Habitat: The native Prairie Smoke is restricted
to northern
Illinois, where it is uncommon. Elsewhere in the state, it is absent.
In Illinois, habitats consist of dry gravelly
prairies and hill prairies. In other states (e.g., Michigan), this
plant has been found in sand prairies and alvars (a habitat
that is dominated by limestone slabs). This
conservative species is found in high quality prairies where the
vegetation is neither too dense nor tall.
Faunal
Associations:
The flowers are cross-pollinated by bumblebees, which seek primarily
nectar from the flowers (personal observation, 2011; Choberka et al.,
2000). These insects are strong enough to force their way into the
flowers. The adults of a leaf beetle,
Graphops marcassita,
have been
observed to feed on Prairie Smoke (Clark et al., 2004). The larvae of
this beetle may also feed on the roots.
Photographic
Location: The wildflower garden of the webmaster in
Urbana, Illinois.
Comments:
Prairie Smoke is an attractive little plant that should be cultivated
more often. The reddish flowers remain attractive for 2-3 months during
both the blooming period and afterwards as the achenes develop. It
is an easy plant to identify because no other
Geum sp. (Avens)
within
Illinois develops achenes with long feathery tails. Only one other
species in this genus,
Geum
rivale (Water Avens), also produces large
reddish flowers. However, Water Avens prefers much wetter habitats than
Prairie Smoke. Within the state, other species in this genus produce
more conventional flowers with 5 spreading petals that are white or
yellow.