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Also known as
Toxicodendron vernix

This shrub, cousin of poison ivy, is even more toxic than the latter. Like poison ivy, its sap contains urushiol to which humans are very sensitive. Exposure to poison sumac can cause dermatitis of varying severity. Contrary to the reaction caused by poison ivy, skin reaction caused by poison sumac looks more like a burn accompanied by blisters.

Poison sumac (Toxicodendron vernix) mature in New-England. Copyright Chris Kreussling on Flicker.
Poison sumac (Toxicodendron vernix) mature in New-England.
Copyright Chris Kreussling on Flicker.
Poison sumac (T. vernix)
Poison sumac (T. vernix)

Leaf

Sumac family, its foliage layout is similar to staghorn sumac. The leaves grow in groups of 7 to 13 per stem. These leaves are tip shaped with a smooth texture (unlike staghorn sumac), and remind also laurel leaves. Its distinctive characteristic is clearly visible under the foliage: the leaf stem (petiole) is red. Each leaflet is about 3 to 4 inches (7.5 to 10 cm) long and 1 to 2 inches wide (2.5 to 5 cm). The complete leaf, consisting the group of leaflets, can reach up to 16 inches (40 cm) in length.

Poison sumac drawing (Toxicodendron vernix).
Poison sumac drawing (Toxicodendron vernix).
Poison sumac drawing (Toxicodendron vernix)
Poison sumac drawing (Toxicodendron vernix)
Poison sumac with little fruits. By Joshua Mayer on Flicker
Poison sumac with little fruits. By Joshua Mayer on Flicker

Trunk and stems

The poison sumac is a small tree that can reach 16 feet (5 m) high in the south, but it rarely exceeds 10 feet (3 m) in the northern United States and in Canada. The trunk diameter can reach 4 inches (10 cm). Unlike staghorn sumac, there is no hair on the stems. The stems can also be red, in spring and early summer.

 Poison sumac (Toxicodendron vernix) in southern Canada. The foliage is lighter than with the American poison sumac. Copyright weedscanada.ca/cashew.html.
 Poison sumac (Toxicodendron vernix) in southern Canada. The foliage is lighter than with the American poison sumac. Copyright weedscanada.ca/cashew.html.
Poison sumac (T. vernix) in southern USA. Notice the red stems. By Andy Jones, Cleveland Museum
Poison sumac (T. vernix) in southern USA. Notice the red stems. By Andy Jones, Cleveland Museum

Flowers and fruits

The flowers are small and discreet, like poison ivy flowers. The flowers in clusters, at the base of the stems, are pale, yellow green. These flowers are very small, often only half an inch (1 cm) in diameter and appear all throughout spring (April – May). The fruit is small, round, striped (like a pumpkin), and yellowish or greenish. Its diameter is about 0,375 inch (1 cm). The fruits, like poison oak and poison ivy, come in drupes near the flowers, at the base of the stems and appear in late summer.

Poison sumac (T. vernix) fruits and leaves.
Poison sumac (T. vernix) fruits and leaves.

Propagation

This vigorous plant is propagated by its seeds, located within fruit. The fruit can drop near the plant or birds can eat the fruit and expel the seeds later in their droppings. Another plant can then push into this place, if the germination is done correctly. Also, the plant spreads using its horizontal rootstocks (rhizomes), which are stem tissue. A root system can cover several feet in diameter.

An area full of Poison sumac (T. vernix). By Aaron Carlson on Flicker
An area full of Poison sumac (T. vernix). By Aaron Carlson on Flicker

Habitat and distribution

In the United States, we can find it from the Mississipi to the Atlantic coast. In Canada, we can meet that shrub in the extreme southern areas of Québec (Montérégie and Outaouais), the southern half of Ontario and the southern tip of Nova Scotia. Fortunately, this shrub is not as common as poison ivy because it prefers moist, fresh and acid open places, such as marsh and pond edges.

 Poison sumac habitat area (Toxicodendron vernix).
 Poison sumac habitat area (Toxicodendron vernix).

Videos about Poison sumac

What does Poison Sumac Look Like?
Facts about poison ivy and explains how to correctly identify poison ivy, poison oak and poison sumac

Resources about Poison sumac

Similar plants looking like poison sumac

Staghorn Sumac

Botanical name: Rhus typhina.
This shrub is in the Anacardiaceae family like our five toxicodendrons but in the Rhus genus. The form of the shrub, the leaflets’ form and design on the stem are reminiscent of  poison sumac. Thankfully, the typical big red velvet flower  reveals we are not looking at poison sumac. Staghorn sumac is common in all the northeastern United States.

Staghorn sumac (Rhus typhina)
Staghorn sumac (Rhus typhina)

More about Staghorn sumac:

Plants To Know: Staghorn Sumac

Elderberry (American and Red)

Botanical name: Sambucus canadensis and Sambucus pubens.
These shrubs grow to 3m or more  and are common in the  eastern United States up to the St. Lawrence Valley in Canada. The leaves look like poison sumac by their fine and slick shape and their layout on the stem. Unlike poison sumac, the stems are green. Unlike poison sumac, the fruits of the American Elderberry are black and those of the Red Elderberry are red.

American Elderberry (Sambucus canadensis) fruits. Source: Elbert-L.-Little,-Jr.
American Elderberry (Sambucus canadensis) fruits. Source: Elbert-L.-Little,-Jr.
American Elderberry (Sambucus canadensis) leaves and flowers. Source: J.M.Garg
American Elderberry (Sambucus canadensis) leaves and flowers. Source: J.M.Garg

More about Elderberry (American and Red):

Red Elderberry