Shrub highly variable, 0.6 - 2 m tall, spreading 1.8 - 3 m

Leaves: alternate, stalked, with three leaflets (trifoliate). Leaves are aromatic when rubbed.

Flowers: either male or female, borne on separate plants (dioecious), or with some bisexual flowers (polygamous), pale yellow, borne at ends of branches, with male flowers in 2.5 cm catkins and female flowers in short spike-like clusters. Flowers mature before or as the leaves expand. Male catkins persist through winter.

Fruit: fleshy with a center stone (drupe), 4 - 5 mm long, bright red, densely hairy, can persist into winter but loses color.

Twigs: highly branched, slender, hairy, aromatic when rubbed, with circular raised leaf scars.

Buds: yellow, tiny, hairy, surrounded by a leaf scar.

Leaflets: very short-stalked or stalkless, medium green, often glossy above, egg-shaped, coarsely toothed, with a lower surface that is hairy when young. The terminal leaflet is 4 - 8 cm long, elliptic to four-sided and tapering to a short pointed tip and a wedge-shaped base. Lateral leaflets about half the size of terminal leaflets and rounded toward the base. Fall color is orange to red to reddish purple.

Similar species: Rhus aromatica var. arenaria differs from Rhus aromatica var. aromatica by having smaller terminal leaflets (1.5 - 4 cm long) that are inversely egg-shaped with blunt to rounded tips, and flowers that mature after the leaves expand.

Flowering: March to April

Habitat and ecology: R. aromatica var. aromatica is infrequent on rocky slopes and bluffs. It occasionally occurs in dry or rocky woods, glades or along roadsides. However, it is planted as an ornamental along roadsides, so many plants in these areas are not spontaneous. It often forms thickets by suckering from the roots.

Occurence in the Chicago region: native

Etymology: Rhus is the Greek name for a species of sumac. Aromatica means aromatic.

Author: The Morton Arboretum

Infrequent throughout the state except on the dunes of Lake and Porter Counties where it is frequent. Found on the dunes about Lake Michigan, on the gravelly bank of the St. Joseph River, on rocky or gravelly banks and bluffs of the Wabash River and its tributaries, and in southern Indiana on bluffs and slopes of streams.

Indiana Coefficient of Conservatism: C = 7

Wetland Indicator Status:

PLANT: ill-scented.

FRUITS: sparsely pubescent.

NOTES: See also parent taxon. Wide-ranging both ecologically and geographically from rim rock, rocky ledges and slopes to canyon bottoms in the deserts, grasslands, chaparral, Madrean woodlands, pinyonjuniper woodlands, ponderosa pine forests, and riparian zones: all AZ cos.; 500-2275 m (1500-7500 ft); Mar-May; w U.S. Material from the w U.S. including AZ has been recognized as Rhus aromatica Aiton var. trilobata (Nutt.) A. Gray, differing in its sparsely pubescent fruits from typical R. aromatica of the e U.S. with villous fruits (Fernald 1941); also, R. aromatica var. trilobata is ill-scented whereas R. aromatica of the e U.S. has a pleasant citrus scent (David Hammond pers. comm.). Several other varieties of Rhus aromatica have been named (based on characters such as leaf size, lobing, and pubescence, and time of flowering) that would occur in AZ (Barkley 1937). Since there are no consistent geographic patterns to the variation in these characters, Rhus aromatica are best treated as a polymorphic species consisting of only the two varieties (e U.S. and w U.S.).

REFERENCES: John L. Anderson, 2006, Vascular Plants of Arizona: Anacardiaceae. CANOTIA 3 (2): 13-22.

Common Name: skunkbush sumac

Duration: Perennial

Nativity: Native

Lifeform: Shrub

Wetland Status: FACU

General: Upright shrubs, deciduous; to 3 m tall, thicket-forming; branchlets brown, becoming gray with age.

Leaves: Alternate, ternately compound or simple; leaflets 1-5 cm long, usualy 3-lobed, margins coarsely toothed; shiny, dark green above, paler green beneath, glabrous or puberulent on one or both sides, turning red in fall.

Flowers: Inflorescence lateral, arising from twigs of the previous years; flowers in dense, spikelike clusters, 1-1.5 cm long; flowers sessile, appearing before the leaves; sepals 5, pinkish; petals 5, yellow, 2-3 mm long.

Fruits: Drupes crowded in clusters; reddish-orange, rounded, 5-8 mm diameter, covered with short, sticky, red hairs.

Ecology: Dry hillsides, canyons, and mesas from 2,500-7,500 ft (762-2286 m); flowers March-June.

Distribution: Most of N.America; from Alberta, CAN, south to s CA, east to MD; south to s MEX.

Notes: A widespread shrub of many biotic communities and habitats; distinguished by being usually 1-2 m tall often with soft, velvety pubescence on stems and leaves (sometimes sparsely-haired); pungent-smelling foliage due to glands all over (hence the common name "skunk bush"); trifoliate leaves with round-lobed leaflets; and clusters of bright red berries that taste like lemons. There is uncertainty surrounding this species. Anderson 2007 suggested that all species of our regional R. trilobata and its varieties be subsumed under R. aromatica. Anderson treated the species as polymorphic, suggesting our western specimens (which he calls R. aromatica var. trilobata) differed from those in the East (R. aromatica) by their sparsely pubescent fruits. He indicated several previously named varieties of this species that lack consistent geographic patterns, and advised they be treated as one complex. Allred and Ivey (2012) continue to use the name R. trilobata and recognize 6 varieties in New Mexico, while acknowledging that the varieties are ill-defined and perhaps not worth recognizing.

Ethnobotany: Leaves are chewed to alleviate stomachache. Oil from fruit is used to treat hair loss. Wild and tended forms very different, so that tended shrubs have long, straight shoots used in basketry. Fruit sour but edible, often mixed with water for a refreshing beverage. Also ground into a meal, after drying in the sun. Fruits, leaves, and bark used in making dye. Navajo used it to treat skin problems and stomach problems. Different parts are used for dying wool and baskets.

Etymology: Rhus is derived from rhous, an ancient Greek name for Sumac, while trilobata means three-lobed.

Synonyms: Rhus trilobata, Rhus aromatica var. trilobata

Editor: SBuckley 2010, Hazelton 2015