Ontario Trees & Shrubs website

Prickly Ash
Zanthoxylum americanum

Other common names: American Prickly Ash, Common Prickly Ash, Northern Prickly Ash, Toothache Tree, Yellowwood

Family: Rue Family (Rutaceae)

Group: Ashes

Distinctive features: Shrub; Alternate compound leaves, thorns. Forms impenetrable thickets.

Flowers: Summer;  Green/Brown;  4 parts (petals)

Leaves: Alternate, Compound, Entire;  Alternate compound.

Fruit/Seeds: Hard fragrant (when scratched) berries.

Habitat: Fields and Open Areas;  Open areas.

Books: Trees in Canada: 220    Newcomb's Wildflower Guide: 170   

Native/Non-native: Native

Status: Common.

Notes: Prickly Ash is not an ash. It was probably thus named because of the resemblance of its leaves to those of Ash trees. Prickly Ash has thorns.

Origin and Meaning of Names:
 Scientific Name: americanum: American

Photographs: 106 photographs available, of which 12 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Prickly Ash (Zanthoxylum americanum)

Upper surface of a Prickly Ash compound leaf.

Prickly Ash (Zanthoxylum americanum)

Underside of the compound leaf.

Prickly Ash (Zanthoxylum americanum)

The leaf arrangement is alternate.

Prickly Ash (Zanthoxylum americanum)

Young leaves coming out in the spring. Prickly Ash leaves come out later than most other shrubs in Ontario.

Prickly Ash (Zanthoxylum americanum)

Prickly Ash (Zanthoxylum americanum)

Nuts developing. When rubbed or crushed, they have a pleasant lemon-like scent.

Prickly Ash (Zanthoxylum americanum)

Close-up of the nuts.

Prickly Ash (Zanthoxylum americanum)

Clusters of ripe nuts on a Prickly Ash shrub, in late summer.

Prickly Ash (Zanthoxylum americanum)

Winter twig, showing thorns. The thorns are opposite.

Prickly Ash (Zanthoxylum americanum)

A closer picture of the thorns. They're wicked!

Prickly Ash (Zanthoxylum americanum)

This early spring photo shows how Prickly Ash frequently grow in dense thickets which, due to the thorns, are almost impossible to penetrate. With care, and if you move slowly, you can get through. But moving quickly through such a grove can be painful!

Prickly Ash (Zanthoxylum americanum)

Another Prickly Ash thicket, in the summer.

Range map for Prickly Ash (Zanthoxylum americanum)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)