Zanthoxylum americanum P. Mill.

  • Family: Rutaceae
  • Common names: American prickly ash, common prickly ash, northern prickly ash, toothache tree.

    Thicket-forming shrub to 3 m (9 ft) in height (rarely a small tree to 6 m tall). Crown many-branched. Bark gray to brown, smooth. Twigs red-brown to gray, pubescent when young, glabrous with age, unarmed or with paired spines 5-15 mm (1/5-3/5 in) long. Leaves alternate, pinnately compound, with 5-11 leaflets. Leaflets elliptic, ovate or oblong, 2-7.5 cm (0.8-3 in) in length, 1-3.5 cm (0.4-1.5 in) wide; pubescent, becoming glabrous; dull green above, veins impressed, paler beneath; asymmetrical base; obtuse at apex; margins crenate or entire; lateral leaflets sessile, terminal leaflet on short petiole; rachis pubescent, becoming glabrous with age. Inflorescence an axillary cyme of small, inconspicuous flowers, pedicels slender and pubescent; calyx absent; petals 5, rounded at apex; pistils 3-5, styles slender, ovules 2; stamens 5, exserted; flowers appear from April to May. Fruit a follicle, 4-5 mm (1/6-1/5 in) long, subglobose to ellpsoid, green to red-brown; seeds 1-2; fruits are strongly aromatic; matures July to September.

    Distribution: Oklahoma and Kansas, north to North Dakota, east to Minnesota and Virginia, south to Georgia and Kentucky. Uncommon.
    Habitat: moist valleys and river bottoms.
    Comment: Zanthoxylum is a Greek word meaning "yellow wood"; americanum refers to North America.
    Medicinal uses: fluidextractum xanthoyli is the trade name for a pungent resin extracted from the fruit and bark. Although an irritant, it is used for rheumatism, as a gastro-intestinal stimulant in flatulence and diarrhea, masticatory for toothache.
    Horticulture: Although introduced to cultivation in 1740, toothache tree is only used ocassionally as an ornamental. Propagation by seed requires either stratification for 10 days at 41F or sowing in fall. Toothache tree can also be propagated by root cuttings and suckers.
    Food uses: used as a honey plant.
    Wildlife uses: fruits are eaten by bobwhites, vireos, pheasants, cottontails and eastern chipmunks.
    NWI status: none

    Distribution in Oklahoma:

    Last update: 9/23/99
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