Alderleaf Buckthorn

Rhamnus alnifolia is a spreading shrub usually 0.5 to 1.5 metres (20 to 59 inches) tall, rarely to 2 m (6+1⁄2 ft), its thin branches bearing deciduous leaves. The thin, deeply veined leaves have oval blades 4.5 to 11 centimetres (1+3⁄4 to 4+3⁄8 in) 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 millimetre (1⁄16 in) wide and have five green sepals but no petals. Female flowers produce drupes 6 to 8 mm (1⁄4 to 5⁄16 in) wide, each containing three seeds. The drupes darken to black when ripe.

It can be found in the southern half of Canada and the northern half of the United States, mostly in the Pacific Northwest. It grows in streambanks and on humid flats near mountains.