Zanthoxylum americanum Mill.

Zanthoxylum americanum Mill. Gard. Diet. ed. 8. 1768
Zanlhoxylum fraxinifolium Marsh. Arbust. 167. 1785. Zanthoxylum fraxineum Willd. Berl. Baumz. 413. 1796. Zanthoxylum ramiflorum Michx. Fl. Bor. Am. 2: 235. 1803. Zanlhoxylum mite Willd. Enum. 1013. 1809. Thy lax fraxineum Raf. Med. Bot. 2: 114. 1830. Mioptrila odorata Raf. Am. Man. Mulb. 37. 1839.
An aromatic shrub, or sometimes a small tree, with a grayish or brownish bark and spreading branches which are armed with sharp, straight or sometimes curved brownish or blackish rather stout stipular prickles ; petioles terete or nearly so, slightly channeled above and on the rachis, more or less pubescent, commonly armed with a few slender pale prickles; leaves odd-pinnate, 1-3 dm. long; leaflets 3-11, ovate to oblong-ovate or oval, 1.5-8 cm. long, 0.7-3. 8cm. broad, acute, short-acuminate, obtuse, or occasionally emarginate at the apex, obliquely rounded or cuneate at the base, crenate or entire, deep-green above,
* These species are repeated in the key because the number of the sepals is doubtful. paler beneath, when young thinly velvety, less so in age, or glabrate, sessile or shortpetiolulate ; pellucid glands usually small, scattered, those between the teeth larger ; flowers in small, sessile, axillary cymes on the branches of the previous season, usually appearing before the leaves; staminate flowers: calyx wanting; petals 4 or 5, greenish or greenishyellow, oblong to oval, occasionally obovate, 2.5-3 mm. long, 1-1.5 mm. broad, fringed at the tip ; stamens 4 or 5, equaling or longer than the petals ; anthers elliptic to ovate ; ovary rudimentary; styles wanting; pistillate flowers: calyx wanting; petals oblong to oval, fringed at the tip ; gynoecium 2-5-carpellarv ; styles rather long ; stigmas capitate ; follicles ellipsoid, 4-6 mm. long, grayish or brownish, stipitate, glandular, the surface wrinkled or pitted ; seeds ovoid, 4-5 mm. long, black, shining, more or less wrinkled.
Type locality : Pennsylvania.
Distribution : Quebec and Ontario to Minnesota, Georgia, Alabama, and Oklahoma.