toothache-tree

Toothache-tree Zanthoxylum americanum
Family: Rutaceae (Citrus)
Branching: Alternate
Other names: Prickly-ash

There is only one species in this genus in Canada. It rarely grows to tree size, but often has the appearance of a sapling, rather than a shrub. Quite thorny, and often grows in dense thickets. The thorns are in pairs, one on each side of the bud (and some of the main trunk and branches). In that respect, they resemble Black Locust, but the difference is that Toothache-tree has a very obvious red, velvety bud, whereas Black Locust buds are quite inconspicuous.

Typical arrangement of two thorns around the red velvety bud and leaf scar

Another view of the twig

A dwarf shoot, and thorns on the main branch