Initially, this annual plant forms a rosette of basal leaves up to 8"
across. Later during the summer, it bolts and become ¾-3' tall,
branching occasionally. The basal leaves are up to 4" long and 1"
across; they are pinnatifid-oblanceolate with several small lateral
lobes and a larger terminal lobe. The leaf margins are smooth,
undulate, or dentate. The basal leaves taper into broad petioles. Lower
alternate leaves along the stems are similar to the basal leaves, but
more irregular in shape. Upper alternate leaves are smaller in size and
less lobed than the preceding types of leaves; sometimes they
are dentate, lacking lobes altogether. Upper alternate leaves
are also sessile, or nearly so. Both basal and alternate leaves are
medium green (tending toward olive green) and glabrous, or nearly so.
Sometimes fine hairs occur along their central veins and margins.
upper stems terminate in racemes of flowers up to 6" long. The flowers
bloom toward the apex of each raceme, while narrow seedpods (siliques)
develop below. Each flower spans about ¾" across, consisting of 4
widely spreading petals, 4 narrow sepals, 6 stamens, and a pistil with
a single style. The petals are are white with conspicuous veins that
are purple or brown; they are oblanceolate to obovate in shape. The
sepals are medium green (or olive green) to purple and linear-oblong in
shape; they are often hairy. The
blooming period usually occurs during the summer for 1-2 months. The
flowers are replaced by cylindrical seedpods that become ½-1¼" long at
maturity. Relative to the central axis of the raceme, they are held
erect. The pedicels of the seedpods are rather
short, but stout, curving upward; they are about ¼" in length. The
seedpods terminate in prominent flattened beaks; their
exteriors are hairless. Each seedpod contains 2 rows of seeds.
Individual seeds are about 2 mm. in length. The root system consists of
a short taproot.
The preference is full sun, mesic to dry-mesic conditions,
and fertile loam, although other soil types are tolerated.
Range & Habitat:
The introduced Garden Rocket
naturalizes in Illinois. So far, naturalized plants have been collected
only in Peoria County (see Distribution
). It has also naturalized
in other states. Garden Rocket was introduced into the United States
from the Mediterranean area of Europe as a salad vegetable. It may have
been introduced even earlier as a contaminant of imported
grain. Habitats of naturalized plants include cropland, fallow fields,
roadsides, areas along railroads, and areas around vegetable gardens
where this plant is cultivated. Disturbed areas with exposed soil are
The flowers are cross-pollinated by bees and
possibly other insects. Two flea beetles, Phyllotreta cruciferae
are known to feed on Garden Rocket. Because its
foliage is quite peppery from the presence of mustard oils, this plant
is probably eaten by mammalian herbivores only when little else is
A vegetable garden at
Meadowbrook Park in Urbana, Illinois.
Because of the dark veins on the petals, the flowers of
Garden Rocket are quite distinct in appearance, and they are rather
large in size for species in the Mustard family. On this basis alone,
Garden Rocket can be distinguished from similar plants in Illinois. The
cylindrical seedpods (siliques) of Garden Rocket are also rather
unusual in having prominent flattened beaks. Other common names of this
plant include Rocket, Roquette, Salad Rocket, and Arugula. A scientific
synonym is Eruca sativa
This plant is still cultivated in North
America as a salad vegetable, where it is used in fresh mixed greens.
The leaves impart a flavor that is spicy and peppery, and they have
relatively high levels of Vitamin C and potassium.