Deciduous aromatic shrubs or small tree, armed with prickles often paired at the nodes (as in Robinia) but not believed to be modified stipules. Twigs moderate, rounded; pith continuous, creamy-white. Buds moderate, superposed, sessile, globose, woolly. Leaf-scars alternate, broadly triangular or 3-lobed;bundle-traces 3; stipule-scars none.

Fig. 173. Zanthoxylum americanum

Fig. 173. Zanthoxylum americanum.

1. Z. americanum Mill. Toothache-Tree. A shrub or small tree, up to 8 m. high; nodal prickles widened at the base; leaf-scars with a conspicuous articular membrane; buds red-rusty. Rich woods, Quebec to North Dakota, south to Georgia and Oklahoma (Fig. 173).