Rhamnus alnifolia

Rhamnus alnifolia is a species of flowering plant in the buckthorn family known by the common names alderleaf buckthorn, or alder buckthorn. Unlike other "buckthorns", this alder buckthorn does not have thorns. It is native to North America, where it is known mainly from the southern half of Canada and the northern half of the United States and California. It can be found in forested habitat.

Description
Rhamnus alnifolia is a spreading shrub usually 0.5 to 1.5 m tall, rarely to 2 m, its thin branches bearing deciduous leaves. The thin, deeply veined leaves have oval blades 4.5 to 11 cm long, pointed at the tip and lightly toothed along the edges. The inflorescence is a solitary flower or umbel of up to three flowers occurring in leaf axils. The tiny flowers are about 1 mm wide and have five green sepals but no petals. Female flowers produce drupes 6 to 8 mm wide, each containing three seeds. The drupes darken to black when ripe.

Uses
Native Americans used the species as a laxative.