A deciduous upright shrub or small tree which can grow up to 6 meters. It blooms with both male and female flowers in winter before leafing out. After male catkins release pollen with the help of the wind, the female flowers above the catkins capture it and a while later a cluster of up to four fruits emerges. The edible nut is encased in a woody light brown shell and they ripen in late summer and early autumn. Commonly grown to form hedges, screens or wild looking thickets. Does best in full sun and rich, well drained soils.