Poison-sumac

Leaves

Form

• Deciduous, alternate
• Pinnately compound
• 7–13 leaflets
• Leaflets long-pointed, stalked
• Lower surface hairless
• Base wedge-shaped

Length

• Leaflets 4–8 cm
• Leaflets and central stalk 15–30 cm

Colour

• Upper surface lustrous dark green
• Lower surface whitened
• Petiole often reddish

Margin

• Smooth

Buds

Form

• Terminal bud conical
• Lateral buds smaller than the terminal bud
• Leaf scars broad, shield-shaped, with many dot-like vein scars in 3 loose groups

Length

• Terminal bud 10–19 mm

Colour

• Purplish-brown

Twigs

Form

• Slender, drooping
• Hairy when young, becoming hairless
• Lenticels prominent

Colour

• Dark green becoming mottled, brownish-yellow

Flowers

Form

• Small
• Open, drooping, branched auxiliary clusters (panicles)

Colour

• Yellowish

Structure

• Dioecious

Fruits

Form

• Small, rounded, berry-like
• Hairless, 1-seeded, thin-fleshed
• In loose, drooping clusters
• Usually remain on the tree throughout winter

Width

• 10–13 mm

Colour

• Glossy white or ivory

Structure

• Drupe

Bark

Form

• Smooth

Colour

• Light grey

Size

Height

• To 6 m

Diameter

• To 10 cm

Tree form

Forest-grown

Trunk

• Slender

Crown

• Small, rounded

Habitat

Site

• Open, swampy woodlands

Associated species

• Willows, black ash, white elm, silver maple, and eastern white-cedar

Range

Rare in Canada; southern Ontario and Quebec