English Oak (Quercus robur)

Though native to western Asia, northern Africa, and the majority of Europe, this deciduous tree was brought to North America in the 1600s and has been cultivated for lumber and ornamental purposes. Within temperate regions, it quickly escaped to the wild and has become increasingly common throughout the years. Though it resembles the white oak (Q. alba) with its rounded leaf lobes, it is distinguished by its smaller leaves and exceptionally long acorns. True to its name, “robur,” meaning “robust” in Latin, this species may live well over 1000 years and grow trunks up to 40 feet in circumference even in suboptimal conditions. 

English oak is an essential resource for a variety of wildlife within its native range, supporting a more biodiverse array of insect herbivores than any other British plant. Though its acorns are valuable food for many birds and small mammals, they contain compounds that may be toxic to humans, horses, dogs, cats, goats, and other larger mammals. It is not classified as an invasive species, but its unrestrained proliferation throughout North America undermines native oak forests. They can be replaced with the native white oak, which provides similar shade and aesthetic benefits.