Shrub to small tree to 10 m tall Stem: stout, smooth, with a sharp spine between end buds. Leaves: opposite to subopposite, stalked (0.6 - 2 cm), shiny dark green above, light green and sometimes lightly hairy beneath, 5 - 15 cm long, 2.5 - 5 cm wide, narrow oblong with a wedge-shaped base and pointed tip, finely round-toothed, with two to four pairs of veins. Flowers: borne in dense clusters, yellowish green, with four petals and four stamens. Fruit: fleshy with two center seeds (drupe), black, spherical, each large seed with one narrow furrow.
Similar species: The typical variety of Rhamnus davurica has leaves that are 4 - 10 cm long with a grayish green lower surface.
Flowering: May to June
Habitat and ecology: Rhamnus davurica was introduced from Asia. It has become a weed at the Morton Arboretum in DuPage County, but is not as invasive as R. cathartica. It is very durable and weedy, growing in thicket borders and disturbed areas. Fire management seems to hep control this and other introduced buckthorns.
Occurence in the Chicago region: non-native
Notes: The Illinois Exotic Weed Act states that this species cannot be purchased, sold, distributed, or planted in Illinois without a permit issued by the Department of Natural Resources.
Etymology: Rhamnus is the ancient Greek name for buckthorn. Nipponicameans Japanese.