Description: This woody plant is a shrub or small tree up to 30' tall that branches occasionally. The upper stems (or branchlets) are covered with dense brown hairs, while the lower stems (trunk or branches) are brown, hairless, and woody. The short trunk is up to 9" across in diameter. The alternate compound leaves are up to 2' long (if not longer); they are oddly pinnate, consisting of 9-31 leaflets. The petioles and central stalks of these compound leaves have scattered brown hairs; the central stalks are often tinted red. The leaflets are up to 5" long and 1" across; they are oblong-lanceolate and serrated along the margins. The upper surface of each leaf is shiny and dark green (becoming red or burgundy during the fall), while the lower surface is pale white. Each leaflet is nearly sessile at the base, and tapers gradually to an elongated tip.
Some of the upper stems terminate
in individual panicles of greenish yellow flowers up to 1' long and ½'
across. Each flower is about ¼" across, consisting of 5 spreading
petals, a calyx with 5 lobes, 5 stamens, and a central pistil. Usually,
the flowers of Staghorn Sumac are perfect (they have both stamens
& pistils), although a few plants produce unisexual flowers
only (either all staminate flowers or all pistillate flowers). The
blooming period occurs during early to mid-summer and lasts about 2-3
weeks. Each flower is replaced by a globoid drupe about 1/6" (4 mm.)
long,
which is densely covered with bright red hairs. This drupe contains a
single seed with a hard coating. The drupes mature during the fall and
persist through the winter; if not eaten, they eventually become dark
brown. The root system is woody and can produce vegetative clones from
long runners. This plant occasionally forms colonies.
Cultivation:
The preference is full to partial sun, mesic to dry conditions, and a
loam, clay-loam, or rocky soil. This woody plant can spread
aggressively by means of underground runners, although the new clonal
shoots are intolerant of regular mowing.
Range &
Habitat:
Staghorn Sumac occurs occasionally in the northern half of Illinois,
while it is uncommon in the southern half of the state (see Distribution
Map). This species is native to the northern half of
Illinois, otherwise it is adventive. Habitats include open upland
woodlands, woodland borders, thickets, rocky barrens with sparse woody
vegetation, dry riverbanks, and areas along railroads. Like other Rhus
spp. (Sumacs), this species thrives on moderate levels of
disturbance. It can invade prairies or meadows, but declines in the
presence of tall canopy trees. Staghorn Sumac has been grown as an
ornamental shrub or small tree in residential areas, although this is
fairly uncommon.
Faunal Associations:
Mostly short-tongued bees, wasps, and flies visit the flowers for
nectar or pollen. Little carpenter Bees (Ceratina spp.) create tunnel
nests in the pith of Rhus spp. (Sumacs), causing
little damage. Various insects and their larvae feed on Sumacs,
including Blepharida rhois (Sumac Flea Beetle) and Poecilocapsus
lineatus
(Four-Lined Plant Bug). The caterpillars of many species of moths are
known to feed on the foliage and others parts of Staghorn Sumac and
other Sumacs (see Moth Table). Also, the
caterpillars of two butterflies species, Calycopis cecrops
(Red-Banded Hairstreak) and Celastrina argiolus
(Spring/Summer Azure), feed on Sumacs. The fruits of Sumacs are eaten
occasionally by upland gamebirds and migrating songbirds during the
autumn and winter (see Bird Table). These fruits are
regarded primarily as emergency food by birds and will be eaten only
when little else is available. The foliage, branches, and twigs of
Sumacs are often browsed by the Cottontail Rabbit and White-Tailed
Deer; the woody material is particularly important as a source of food
during the winter. In general, the ecological value of Sumacs to
wildlife is fairly high.
Photographic Location:
A gravelly area along a railroad in Urbana, Illinois.
Comments:
This is the tallest Sumac species in Illinois. It is less common than Rhus
glabra (Smooth Sumac). Staghorn Sumac is easy to identify in
the field because its young branches are covered with dense brown
hairs. These hairs have the appearance of "velvet" on a deer's antlers,
hence the common name. Other Sumacs have young branches that are less
hairy or hairless (usually the latter). Like Smooth Sumac, Staghorn
Sumac has central leaf stalks without wings, and both Sumacs have
leaflets that are serrated along the margins and pale white on their
undersides. However, the central leaf stalks of Staghorn Sumac have
scattered brown hairs and its bright red drupes are much hairier than
those of Smooth Sumac. Another scientific name of Staghorn Sumac is Rhus
typhina.