Shrub to small tree 2 - 7 m tall Leaves: pinnately compound, stalked, with seven to thirteen leaflets. Flowers: borne axillary in an inflorescence to 20 cm long, spreading or hanging down. Fruit: fleshy with a center stone (drupe), clustered, grayish white, 4 - 5 mm long, spherical. Bark: gray and mostly smooth. Twigs: covered in a whitish waxy coating (glaucous), hairless. Leaflets: short-stalked, 4 - 5 cm long, oblong to elliptic or inversely egg-shaped and tapering at both ends, non-toothed. Fall color is orange to red.
Similar species: A few Rhus species may be mistaken for Toxicodendron vernix, but they all have red fruit. In addition, Rhus typhina and Rhus glabra have toothed leaflets, and Rhus copallina and has winged stalks between the leaflets.
Habitat and ecology: Locally common in bogs, also growing in shaded marsh borders of dunes.
Occurence in the Chicago region: native
Notes: Avoid touching this plant, as it contains a toxic compound called urushiol. Do not burn it, as the toxin is released into the air and can be inhaled. After contact with urushiol, a person sesitive to the toxin becomes itchy, and within 24 - 48 hours the skin blisters and reddens. If tools or clothing have been contaminated, they should be washed with hot water and soap.
Etymology: Toxicodendron means "poison tree." Vernix means varnish.
Shrub to 5 m, often branched from the base; lfls 7-13, oblong to obovate or elliptic, 4-5 cm, acute to acuminate, entire, acute at base, glabrous or nearly so; infls to 2 dm; fr grayish-white, 4-5 mm. Swamps, usually in shade; s. Me. and sw. N.S. to Minn. and sw. Ont., s. to Md., O., and Ind.; Del. to Fla. and Tex. (Rhus v.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Poison sumac is frequent in low ground about lakes and in bogs in the lake area. South of this area I have found it in springy areas as shown on the map. This species must have a springy or bog habitat in which to live. I have had the opportunity to watch the species in three bogs that were drained, and it gradually died out.
Indiana Coefficient of Conservatism: C = 10
Wetland Indicator Status: OBL
Diagnostic Traits: small tree or tall shrub; pinnately compound leaves with 7-13 leaflets; petioles glabrous; inflorescences axillary; drupe fruits pale, without red hairs.