Eucalyptus gunnii, commonly known as cider gum,is a species of small to medium-sized tree endemic to Tasmania. It has mostly smooth bark, lance-shaped to egg-shaped adult leaves, flower buds in groups of three, white flowers and cylindrical to barrel-shaped fruit. Flowering has been recorded in all months from September to April with peak flowering in December, January and February. Eucalyptus gunnii is a tree that typically grows to a height of 25 m (82 ft) and forms a lignotuber. It has smooth, mottled, white or grey bark, sometimes with persistent rough bark on the lower trunk. Young plants and coppice regrowth have sessile leaves arranged in opposite pairs.