Carrot family (Apiaceae)
This herbaceous plant is a winter or
summer annual about 4-18" tall and
similarly across; it branches dichotomously. Initially, a few basal
leaves develop during the autumn or spring, but during late spring this
plant bolts The stems of bolting plants are medium green, terete, and
glabrous. Alternate leaves occur along the entire length of these
stems, becoming smaller in size as they ascend. They vary in size from
½–3½" long and similarly across. The leaves are medium green,
glabrous, and bipinnatifid or tripinnatifid in structure; they branch
dichotomously and somewhat irregularly, forming narrowly linear to
filiform lobes. These lobes are up to ¾" (20 mm.) long and about 0.5–1
mm. across. The narrow petioles of the leaves are nearly zero to 2"
long; they are mostly green and glabrous, although the bases of these
petioles have sheaths with white- to brown-membranous margins.
axillary and terminal umbels of flowers are produced in abundance.
These umbels are usually compound, consisting of 2-3 umbellets (rarely
with 4 umbellets),
although sometimes they are simple. The compound umbels span about
(20-32 mm.) across; their peduncles (basal stalks) are ¼–1" (6-24 mm.)
long. The rays (basal stalklets) of the umbellets are ascending
and divergent; they are ¼–¾" (6-20 mm.) in length. Individual
umbellets span ¼–½" (6-12 mm.) across, consisting of 5-15 flowers;
their pedicels are nearly zero to ¼" long. The peduncles, rays, and
pedicels of each compound umbel are medium green, glabrous, and
straight. Both the umbels and umbellets lack floral bracts. Individual
flowers are only 1-2 mm. across when they are fully open. Each flower
consists of 5 white petals, a toothless green calyx, 5 stamens, and a
2-celled ovary with a pair of short styles. The blooming period occurs
during the summer and autumn, lasting about 2-3 months. Only a few
flowers are in bloom at the same time.
Afterwards, the flowers are
replaced by dry fruits (schizocarps); immature fruits are light green,
while mature fruits turn brown; the latter soon fall to the ground.
schizocarp consists of 2 hairless seeds. Individual seeds are 1.0–1.5
mm. long and asymmetrically ellipsoid in shape; one side of each seed
is flat to slightly concave, while the other side is convex and
conspicuously ribbed (3 ribs that are separated by 2 furrows). The root
system consists of a slender taproot. This plant reproduces by
The preference is full sun and
moist conditions; a variety of soil types are tolerated. This plant
will colonize drier ground, but it is vulnerable to hot dry weather. In
some situations, this plant can spread aggressively, although this has
not been a problem (thus far) in Illinois.
The non-native Fir-leaved Celery is a
rare weed in Illinois. So far, it
has occurred only in Champaign County (see Distribution
probably native to subtropical areas of Central and South America.
However, it has spread to both subtropical and temperate areas
throughout the world. Illinois appears to lie along the northern
range-limit of this species; it is more common in southeastern and
southwestern United States. In Illinois, Fir-leaved Celery was growing
in low shrubbery near a parking lot in downtown Champaign, Illinois. It
also occurred nearby in weedy turf grass along a roadside. In general,
habitats of this plant include cropland, abandoned fields, roadside
ditches, areas along railroads, gardens, neglected lawns, and areas
around landscape shrubs. Fire and regular mowing are not tolerated.
Nonetheless, this plant prefers habitats with a history of
for Fir-leaved Celery are not well-understood for North America.
White-tailed Deer browse on the foliage (Everitt et al., 1999).
Livestock, including dairy cattle, sometimes browse on the foliage of
plant, as there have been some concerns about whether or not it can
taint the flavor of milk.
Location: Low shrubbery and weedy turfgrass in downtown
Champaign, Illinois, where this plant has persisted for several years.
One of the photographs was taken indoors.
Sometimes the scientific name of
Fir-leaved Celery is spelled
and another scientific name of this plant is
It also has other common names, including Marsh
Parsley and Slender Celery. Fir-leaved Celery is remarkable for its
narrowly lobed leaves and abundant umbels of tiny flowers. It is
possible to confuse this plant with two other groups of annual plants
in the Carrot family, viz. species of Mock Bishop-weed (Ptilimnium
spp.) and Scaleseed (Spermolepis
spp.), as they also have
leaves with very narrow lobes and small white flowers. Species of Mock
Bishop-weed differ by having larger compound umbels of flowers with
more umbellets and the presence of floral bracts at the bases of their
compound umbels. Species of Scaleseed can be distinguished by the
bractlets at the bases of their umbellets and the presence of tubercles
or bristles on their seeds. In contrast, Fir-leaved Celery lacks both
floral bracts and bractlets and its seeds lack tubercles or bristles.