A fossil leaf of Corylopsis Sieb. & Zucc., (Hamamelidaceae; Saxafragoid clade) and several other Hamamelidaceae-like leaves are described from the middle Eocene (49-50 MA) Republic flora of eastern Washington State, USA. The fossil Corylopsis leaf is similar to several extant species, particularly with the presence of prominent agrophic veins and ladder-rung-like tertiaries at right angles to the secondaries. The leaf is 1.9 cm wide, of incomplete length, with an asymmetrical base. Teeth are concave apical, straight basal, with simple apices. Several other Hamamelidaceae-like leaves present in the Republic flora are simple, symmetric, range from 2.1 to 8.7 cm in length, from 0.9 to 4.3 cm in width, have a L/W ratio of 2.0 to 2.3 and are generally elliptic in shape. Bases are typically asymmetric and cordate to rounded. Leaf apices are not preserved. Venation is craspedodromous with secondary veins produced alternately from the midvein. Compound agrophic veins varying from 1 to 2 are produced by the secondaries. Ladder-rung-like tertiary veins are formed at right angles to the secondaries. Tertiaries and quaternaries comprise usually 5-sided areoles containing 5th order veins. When visible, teeth are generally concave apical, straight basal, with a simple apex. Today Corylopsis, an ornamental shrub commonly called "Winter Hazel", is known only from the Himalayas to Japan, but was more widely distributed in the past. The fossil record of Corylopsis is based primarily on seeds that occur from the Eocene throughout much of the Tertiary in Europe, the Eocene of eastern North America, and from one previous report of a leaf from the Eocene of Alaska. The presence at Republic of Corylopsis and other Hamamelidaceae-like leaves including the previously described Langeria magnifica demonstrates a high diversity in this group during the middle Eocene of western North America.

Key words: Corylopsis, Eocene, fossil leaf, Hamamelidaceae, North America