Kumquats or cumquats are a group of small fruit-bearing trees in the flowering plant family Rutaceae, either forming the genus Fortunella, or placed within Citrus sensu lato. The edible fruit closely resembles that of the orange (Citrus sinensis), but it is much smaller and ovular, being approximately the size and shape of a large olive. They are slow-growing evergreen shrubs or short trees, from 2.5 to 4.5 meters (8 to 15 ft) tall, with dense branches, sometimes bearing small thorns.