Northern Prairie Wildlife Research Center
Southern Wetland Flora
Field Office Guide to Plant Species
Zanthoxylum clava-herculis L.
- Family: Citrus (Rutaceae)
- Flowering: April-May
- Field Marks: This shrub or tree is characterized by flat-based prickles, pinnately compound
leaves with yellow glands along the margins in notches formed by the teeth, compound cymes
with small greenish yellow flowers, and follicles.
- Habitat: Moist to dry soils along roads, pineland depressions, sandy areas, roadsides,
- Habit: Shrub or tree to 30 feet tall; trunk up to 18 inches in diameter; crown rounded.
- Bark: Gray, covered with flat-based prickles.
- Twigs: Gray, sometimes with flat-based prickles.
- Leaves: Alternate, pinnately compound, with 5-19 leaflets; leaflets lanceolate to ovate, pointed
at the tip, rounded at the asymmetrical base, crinkled along the margins with yellowish glands
in notches formed by the teeth, smooth but dotted on both surfaces, up to 3 inches long, usually
with prickles in the leaf axils.
- Flowers: Many in compound cymes.
- Sepals: 4-5, minute, green, free from each other, or absent.
- Petals: 4-5, greenish yellow, free from each other, up to 1/5 inch long.
- Stamens: 4-5.
- Pistils: 1-5, free from each other.
- Fruits: Follicles red, smooth, up to 1/4 inch long; seeds spherical, shiny, black, up to 1/6 inch
- Notes: This tree is sometimes called toothache tree because of the numbing effect of the inner
bark when placed against the gum.
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