Common Name: 

Five species of deciduous shrubs or small trees; branches and buds with stellate pubescence.  Leaves resemble those of Corylus, simple, alternate, ovate to obovate, margins toothed, and base oblique, petioles short, large stipules.  Flowers appear in short, axillary clusters at or after leaf fall or before new growth in spring, fragrant, calyx 4-lobed and persistent, 4 petals, linear and crumpled in the bud, to 2 cm, mostly yellow, but also red and orange.  Fruit 2-parted, with 2 black seeds that are explosively released when ripe.  Native to North America, Europe and Asia.
Hamamelis: from the Greek for pear-shaped fruit, but apparently applied to a different plant.