Cashew family (Anacardiaceae)
Description: This native woody shrub is 2-8' tall. Depending on the variety, it is variable in size and branching habit. Fragrant Sumac can be an erect shrub with ascending branches, or it can be a low shrub with spreading branches. The trunk and lower branches are greyish brown and woody, while the upper branches are more or less pubescent. The alternate leaves are trifoliate. The individual leaflets are up to 3" long and 1½" across, although they are often half this size. The terminal leaflet is somewhat larger than the lateral leaflets. They are elliptic, oval-ovate, oblanceolate, or obovate in shape, coarsely crenate or shallowly cleft along their margins, and green, yellowish green, or red. The upper surface of each leaflet is glabrous to finely pubescent (canescent), while the lower surface is sparsely pubescent to softly hairy. Each leaflet is sessile, or it has a short petiole. The crushed foliage has a pleasant bittersweet fragrance. Occasionally, short spikes of flowers or panicles of floral spikes are produced from the axils of the leaves. These flowers can appear before or during the early development of the leaves. Each floral spike is up to 1" long. The individual flowers are greenish yellow, short-tubular in shape, and about 1/8" long; they can be perfect or unisexual (male or female). The blooming period occurs during the spring. During the summer, the flowers are replaced by hairy red drupes. Each drupe is up to ¼" across and globoid-ovoid in shape; it contains a single stone (seed with a hard coat). The root system consists of a woody branching taproot.
Cultivation: The preference is full or partial sun, dry conditions, and soil that is sandy or rocky. However, this shrub will adapt to mesic conditions with fertile loamy soil if there is not too much competition from other species of plants.
Range & Habitat: Aromatic Sumac is occasional in parts of southern, western, and northern Illinois; it is uncommon or absent from east central Illinois (see Distribution Map). This map combines the distribution of the different varieties of Aromatic Sumac. Aromatic Sumac is more tree-like and erect in southern Illinois, but a low spreading shrub elsewhere in the state. Habitats include thinly wooded bluffs, upland rocky woods, barren rocky areas, limestone glades, sandy savannas, sand prairies, and sand dunes. Aromatic Sumac is often cultivated as an ornamental shrub in yards or along buildings and city streets.
Faunal Associations: The nectar and/or pollen of the flowers attract small bees (especially Halictid & Andrenid bees), Syrphid flies, and a variety of other flies. Small Carpenter bees (Ceratina spp.) create tunnel-nests in the pith of sumac stems. The adults and larvae of Blepharida rhois (Sumac Flea Beetle) feed on the foliage of Aromatic Sumac and other species of sumac (Rhus spp.). Other insects that reportedly feed on sumac include larvae of Oberea ocellata (Sumac Stem Borer), Melaphis rhois (Sumac Gall Aphid), larvae of Asphondylia integrifoliae (Sumac Flowerbud Gall Midge), and the caterpillars of several moths and butterflies (see Moth & Butterfly Table). The hairy red drupes of sumac are largely used as emergency food by birds during the winter or when little else is available. Nonetheless, a large number of bird species have been observed eating these drupes (see Bird Table for a listing of these species). The White-Tailed Deer browses on the woody stems and leaves, while the Cottontail Rabbit gnaws on the bark of sumac during the winter.
Photographic Location: The floral spikes were photographed along a city street in Champaign, Illinois. The trifoliate leaves and hairy red drupes were photographed on a stabilized sand dune near Lake Michigan at the Indiana Dunes State Park in NW Indiana.
Comments: Fragrant Sumac is smaller and less aggressive than Rhus glabra (Smooth Sumac) and Rhus typhina (Staghorn Sumac). The flowers of Fragrant Sumac bloom earlier in the spring and its drupes ripen earlier in the summer than these other species. Its compound leaves are trifoliate, while the odd-pinnate leaves of other Sumacs in Illinois have many more leaflets than this. These other Sumacs also lack the aromatic foliage of Fragrant Sumac.