Prairie
Parsley
Polytaenia nuttallii
Carrot family (Apiaceae)
Description:
This plant is a biennial or
short-lived perennial that persists as a
low rosette of basal leaves for 2-4 years. The blades of these basal
leaves are up to 6" long and 5" across; they are bipinnate-pinnatifid
or pinnate-pinnatifid in structure and triangular in outline.
Individual leaflets (or subleaflets) are moderately to deeply divided
into pinnate lobes; these lobes usually have a few coarse teeth along
their margins. The surface of basal blades is medium green and
glabrous (or nearly so). The petioles of the basal leaves are up to 4"
long and they are covered with short fine pubescence to a greater or
lesser extent. In addition, the leaflets of the basal leaves have
conspicuous petiolules (basal stalklets). The petiolules of the
terminal leaflets are longer than those of the lateral leaflets.
Eventually, this plant bolts to produce a single
flowering stalk with a few alternate leaves. This stalk is light green
to pale brownish red, terete (round in cross-section), somewhat stout,
and 1½-3' tall. It is unbranched, except toward the apex, where the
umbels of flowers occur, and usually it is covered with short fine
pubescence to a greater or less extent. The alternate leaves are up to
3" long and 3" across, pinnate-pinnatifid in structure, triangular in
outline, and sessile; they become smaller in size as they ascend the
stem. Similar to the basal leaves, the leaflets of alternate leaves are
moderately to deeply divided into pinnate lobes; these lobes usually
have a few coarse teeth along their margins. The surface of alternate
leaves is medium green and glabrous (or nearly so). The central stalk
terminates in a few compound umbels of flowers that span 1½-3" across.
In addition, lateral compound umbels of flowers often develop
from the axils of upper leaves on peduncles 2" long or more. Depending
on their stage of development, the tops of these umbels are
dome-shaped
to nearly flat. A typical umbel will have about 10-15 congested
umbellets, and each umbellet will have 10-15 flowers. The rays
(stalklets) of both the umbels and
umbellets are light green, angular,
and more or less covered with short fine pubescence. Both umbels and
umbellets lack significant floral bracts. When such bracts are present,
they are small in size, linear in shape, and soon wither away. Each
flower has 5 yellow petals with incurved tips, a light green or
yellowish green calyx with 5 minute ovate teeth, 5 stamens, and a
pistil. Individual flowers are about 1/8" (3 mm.) across. The blooming
period occurs from mid-spring to early summer for about 1 month. Each
flower is replaced by a dry fruit (schizocarp) that becomes 6-9 mm.
long at maturity. Immature fruits are green, but they later become
yellow, and finally brown. Each fruit consists of a pair of seeds that
develop winged margins at maturity. These seeds are distributed
to some extent by
the wind. The root system consists of a deep taproot.
Cultivation:
The preference is full sun, mesic to dry conditions, and soil
containing loam, rocky material, or sand. The seeds can be difficult to
germinate, requiring a winter dormancy of about 120 days, and each
plant is rather slow to develop after germination has occurred.
Range
& Habitat: The native Prairie Parsley occurs in
scattered areas
of
northern, southern, and west-central Illinois, where it is fairly
uncommon. Populations of this plant within the state appear to be
declining. Illinois lies along the NE range limit of this plant.
Habitats include upland prairies, hill prairies, limestone glades,
chert glades, thinly wooded bluffs, and savannas. Prairie Parsley is an
indicator plant of original prairie. It is rarely found in disturbed
areas. This conservative species may require occasional wildfires to
remove excess brush and debris, and to facilitate germination of the
seeds.
Faunal
Associations: The tiny flowers attract primarily
small bees, miscellaneous flies, and occasional wasps (Robertson,
1929). Prairie Parsley is one of the species in the Carrot family that
the oligolectic bee, Andrena
ziziae, visits for pollen and nectar. The
caterpillars of a butterfly, Papilio
polyxenes asterius (Black
Swallowtail), feed on the foliage of this plant. Cattle and other
mammalian herbivores browse readily on the non-toxic foliage.
Photographic Location:
The wildflower garden of the
webmaster in Urbana, Illinois.
Comments:
Most people might regard Prairie Parsley as another weed, but it is a
conservative native plant with high fidelity to prairies. This plant is
perhaps at its most attractive when its fruits have reached the showy
yellow stage. The native Prairie Parsley in Illinois should not be
confused with either Wild Parsnip (Pastinaca
sativa) or Golden Alexanders (Zizia aurea). Like
Prairie Parsley, Wild Parsnip and Golden Alexanders
have compound umbels of small yellow flowers, but they differ by having
simple-pinnate leaves with leaflets that are less lobed. Another
species, Flat-Leaved Parsley (Petroselinum
crispum neapolitanum), has compound leaves and
compound umbels of flowers that are very similar to those of Prairie
Parsley, but Flat-Leaved Parsley differs by having mature seeds that
lack winged margins.