poison sumac Identification (Toxicodendron vernix)

Use these quick visual checks for Toxicodendron vernix.

• Leaves are alternate and compound, usually with 7-13 smooth-edged leaflets.
• Leaflets are oval to oblong, often with a pointed tip; the end leaflet is usually on a longer stalk.
• Plants grow as a tall shrub or small tree, often 5-20 feet (1.5-6 m) tall.
• Fruit hangs in loose clusters from the leaf axils; each drupe is pale gray to whitish and about 1/8-1/4 inch (3-6 mm) wide.

Check the leaflet count and the pale hanging fruit together for the most useful field clues.

Poison sumac shows useful visual changes from sapling form through flowering and fruiting stages.

• Young plant: Young plants are slender and upright, with smooth gray stems and proportionally larger-looking compound leaves on long stalks, before the crown broadens.
• Mature plant: Mature plants become a tall shrub or small tree, often 6-20 feet (1.8-6 m) tall, with thicker stems and a looser, more openly branched crown.
• Flowering stage: Flowering branches carry drooping clusters from the leaf axils, with many small greenish flowers that are less visually prominent than the hanging cluster shape.
• Fruiting stage: Fruiting clusters are more conspicuous, hanging below the leaves and filled with smooth ivory to pale greenish berries, unlike the subtler flower clusters.

In spring, poison sumac leafs out with glossy leaflets that often look bronzy or orange-tinted before turning green. By early summer, hanging clusters of small greenish flowers can be visible. Late summer into fall brings drooping clusters of pale gray to white berries. In fall, the foliage often turns bright yellow, orange, or red before dropping, which makes the smooth gray stems and open branching easier to see.

A few wetland shrubs and small trees are regularly mistaken for poison sumac.

Toxicodendron vernix is native to eastern North America, from parts of the northeastern and Great Lakes region south through the eastern United States. Its range overlaps with many harmless shrubs, so geography alone is not enough. Habitat is more useful. This species is strongly tied to acidic wetlands such as swamps, bog margins, wet woods, and peaty thickets. Finding a suspected plant with standing water or saturated soil nearby helps narrow the identification, especially away from dry uplands.

• Skin contact: All parts contain urushiol, an oily sap that can trigger a strong allergic skin rash in humans and pets after contact with leaves, stems, or roots.
• Smoke exposure: Burning poison sumac can carry urushiol in smoke. Inhaling it is harmful to humans and pets because it can irritate exposed tissues, including the airways.