Northern Prickly Ash

zanthoxylum americanum

The Northern Prickly Ash (Zanthoxylum americanum) is a fascinating, aromatic shrub native to North America. Despite its common name and ash-like pinnate leaves, it is not a true ash at all, but rather a member of the citrus family (Rutaceae). This understory specialist is historically famous for its medicinal qualities, particularly its ability to alleviate toothaches. When any part of the plant—especially the bark or leaves—is chewed, it releases active chemical compounds that induce a powerful tingling and numbing sensation in the mouth.

Habitat: Typically found in moist or rocky open woodlands, forest edges, thickets, and along riparian corridors.

Appearance

This deciduous shrub typically grows between 150 to 500 centimeters tall, forming dense, multi-stemmed thickets. Its most defining physical features are the sharp, dark-brown prickles paired at the bases of its pinnate compound leaves, which consist of 5 to 11 ovate leaflets. In spring, before the leaves fully expand, it produces small, inconspicuous yellow-green flowers. By late summer, these develop into small, clustered, bumpy reddish-brown seed capsules that split open to reveal shiny black seeds, all while emitting a strong, citrusy aroma when crushed.

KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderSapindalesFamilyRutaceaeGenusZanthoxylum

Northern Prickly Ash

Interesting facts

Because it belongs to the citrus family (Rutaceae), its leaves contain oil glands that emit a fragrant, lemon-like scent when bruised.

Native Americans and early European pioneers chewed the bark of this plant to relieve severe toothaches, leading to its famous nickname, the 'Toothache Tree'.

While most mammalian browsers avoid it due to the sharp prickles and numbing chemicals, it is highly sought after by specialized lepidopteran larvae.

Special abilities

Produces secondary metabolites like herculin in its bark and leaves, which numb oral tissues to deter mammalian herbivores.

Glands on the leaves secrete highly aromatic essential oils that repel destructive pests while attracting specific pollinators.

Possesses sharp, flat-based thorns along its twigs and petioles that physical protect the shrub from larger browsers.

Measurements & details

Length: 150-500 cm
Lifespan: 15-50 years

Diet & Feeding

As a photosynthetic plant, it manufactures its own sugars using sunlight, water, and carbon dioxide, while absorbing minerals through its root system.

Primary Foods

Sunlight
Water
Carbon dioxide
Soil nutrients

Foraging Method

Photosynthesis

Ecological connections

host plant

Giant Swallowtail

Papilio cresphontes

Serves as a vital host plant for caterpillars of Canada's largest butterfly.

mutualism

Honey Bee

Apis mellifera

Feeds on the small yellow-green spring flowers to harvest nectar.

eaten by

American Robin

Turdus migratorius

Consumes the ripe red berries in late autumn and disperses the seeds.

Traits

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Also known as

No aliases listed yet.

Collections

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify Northern Prickly Ash?

The easiest way to identify Northern Prickly Ash is to use the Snappit nature identifier app.

How long is Northern Prickly Ash?

150-500 cm

How long does Northern Prickly Ash live?

15-50 years

What does Northern Prickly Ash eat?

As a photosynthetic plant, it manufactures its own sugars using sunlight, water, and carbon dioxide, while absorbing minerals through its root system.

Where is Northern Prickly Ash usually found?

Typically found in moist or rocky open woodlands, forest edges, thickets, and along riparian corridors.

How does Northern Prickly Ash hunt?

Photosynthesis