Description:
This is a large shrub or small tree that is 8-30' tall at maturity,
forming a long narrow trunk and either a sparsely branched or
unbranched crown. The trunk is up to 6" across (rarely up to 1'
across), terete (circular in circumference), and more or less spiny.
Trunk bark is light gray or light brown and relatively smooth, but
becoming increasingly rough with age. The spines are relatively stout,
but sharp, and they are often arranged in curvilinear patterns around
the surface of the trunk. In addition, large petiole-scars persist on
the trunk (sometimes almost surrounding it) that have a flattened
U-shape. Ascending lateral branches are sparingly produced (if at all)
during later stages of development. These branches are rather stout,
terete, spiny, and either light gray or light brown. Like the trunk,
they also have persistent leaf-scars. Alternate compound leaves occur
toward the apex of the trunk and the apices of any lateral branches;
they are widely spreading. These compound leaves are 2-4' long and
1¾-3½' across; they are mostly bipinnate, although some leaves are
partially tripinnate. Along the primary rachis of each compound leaf,
there are several pairs of simple-pinnate leaves. Along the secondary
rachises of these simple-pinnate leaves, there
are 5-13 leaflets, although some of these leaflets are replaced
by a trifoliate arrangement of 3 leaflets when the compound
leaves are tripinnate.
Individual leaflets are 2-3½" long and 1½-3" across; they
are narrowly ovate to broadly ovate in shape, while their margins are
serrated.
The leaflet bases are narrowly rounded to rounded and often asymmetric,
while their tips are somewhat elongated
and narrow. The upper surface of leaflets is medium to dark green and
glabrous, while their lower surface is pale green to nearly white and
either glabrous or slightly pubescent. When leaflet pubescence occurs,
it is typically restricted to the lower side of the central veins.
The leaflets have short petiolules (basal stalklets) about ¼" long. The
petioles of the compound leaves are up to 1½' long and their bases
are stout. The petioles and rachises of the compound leaves are light
green, brownish green, or light red; they are glabrous and sometimes
spiny on their undersides. The apex of the trunk and apices of any
lateral
branches can produce 1-3 inflorescences that are individually 1½-4'
long
and 1-3' across. These inflorescences are compound panicles of floral
umbellets. During the blooming period, the branches (peduncles,
pedicels, etc.) of each inflorescence are light green to reddish green
and pubescent. Each umbellet is about ¾-1" across and globoid in shape,
consisting of 12-20 flowers and their pedicels. In each inflorescence,
the flowers are either all perfect or there is a mixture of perfect and
unisexual flowers. Each flower is up to ¼" long, consisting of 5
triangular petals that are white, a short-tubular calyx that is light
green, 5 exerted stamens (for perfect or male flowers), and a 5-celled
ovary with 5 styles (for perfect or female
flowers). The blooming
period occurs from mid- to late summer. The flowers are fragrant
(reported to be lemony). Afterwards, the flowers are replaced by
small berries. At maturity during the autumn, these berries
are about ¼" long, ovoid-globoid in shape, finely ribbed, and
either dark blue or black. These berries have thin fleshy interiors and
they contain 2-5 flattened seeds. At this time, the branches of the
fruiting inflorescence become red. The root system has long fleshy
rhizomes, from which clonal offsets can develop. The deciduous leaves
turn yellow (less often, bronze red) during the autumn.
Cultivation:
The preference is partial sun, moist to mesic conditions that are
well-drained, and fertile loamy soil. However, this tree (or shrub)
also adapts to soil that contains rocky material, clay, or sand, and it
has a wide pH tolerance. The flowers and berries are not produced until
the third or fourth year of development, if not later. While this tree
(or shrub) can be planted north of its range (to about Zone 5), it may
die back to the ground if there is exposure to severe winter cold.
Range
& Habitat: The native Devil's Walkingstick (
Aralia spinosa) is
occasional in southern Illinois, while in the rest of the state it is
absent (see
Distribution
Map). Illinois lies along the northwest range
limit of this species. However, sometimes it is cultivated as a
landscape plant in areas that are north of its natural range. Habitats
include upland woodlands, lowland woodlands, wooded slopes, wooded
ravines, bluffs, woodland borders, wooded areas along streams,
savannas, and thickets. Devil's Walkingstick prefers areas with a
history of disturbance from occasional wildfires, logging, etc., as
this reduces excessive shade from overhead canopy trees.
Faunal
Associations: The flowers are cross-pollinated primarily
by bees. Both
nectar and pollen are available as rewards to such floral visitors.
Very few insects are known to feed destructively on Devil's
Walkingstick (
Aralia
spinosa). Sometimes this tree (or shrub) becomes
defoliated
during early autumn by the polyphagous
Epicauta funebris
(Margined
Blister Beetle). The abundant berries are eaten by such
birds as the Cedar Waxwing, White-Throated Sparrow, Swainson's
Thrush, and Wood Thrush. Until it became extinct, the Passenger
Pigeon also fed on the berries. Mammals that have been observed to feed
on the berries include the Black Bear, Red Fox, Striped Skunk, and
Eastern Chipmunk. These fruit-eating animals spread the seeds of this
tree (or shrub) to new locations. White-Tailed Deer reportedly browse
on the foliage upon occasion.
Photographic
Location: A moist wooded slope in Pope County of southern
Illinois.
Comments:
Because of its exposed spiny trunk and exceptionally large compound
leaves, the Devil's Walkingstick (
Aralia
spinosa) is sometimes grown
as a curiosity in landscaped areas. It produces large panicles of
fragrant flowers during the summer and dark berries during the autumn.
This woody species, which is native to southern Illinois, is often
confused with a similar species,
Aralia
elata
(Japanese Angelica Tree). The latter has been introduced into North
America as an
ornamental landscape plant, where it is often cultivated. Devil's
Walkingstick can be identified by its larger compound leaves (up to 4'
long) and larger panicles of flowers or fruit (up to 4' long). In
addition, this native shrub has leaflets with conspicuous petiolules
(about ¼" long), while the leaflets of Japanese Angelica Tree are
sessile (or nearly so). On the leaflet undersides of Devil's
Walkingstick, the lateral veins don't extend all the way to the leaflet
margins (by curving parallel to them), whereas these veins do extend to
the leaflet margins on Japanese Angelica Tree. Sometimes
Aralia spinosa
is referred to as Hercule's Club, but this common name more properly
applies to another woody species,
Zanthoxylum
clava-herculis. While
this latter species has a superficially similar appearance to the
Devil's Walkingstick, it is a member of the Citrus family (Rutaceae).
This latter tree (or shrub) has a more southern range and it is not
found in
Illinois. Unlike Devil's Walkingstick, its compound leaves are
simple-pinnate and smaller in size.