Scientific Name
Phellodendron amurensis
The Amur cork tree is native to the far eastern region of Asia, near the Amur River, which forms part of the border between Russia and China. For urban use, this tree seems to have much in its favor, including adaptability to varying soils and climates, resistance from disease and pests, and tolerance of drought and pollution. Even so, it has not been widely adopted in the United States and may best be considered a novelty for now. It is a medium-sized tree at maturity, typically reaching about 50 feet tall with a similar spread, which is also about the size of the Colorado state champions.
The leaves are compound, with five to 11 leaflets, and turn an unremarkable yellow in the fall. The bark of older trees is a major point of interest, developing thick corky layers separated by vertical fissures. The annual cork layers can be seen on this Regis specimen and will compress slightly when pressed, similar to cork from oak trees used for wine stoppers. However, cork from this species is used mainly for industrial purposes.
Amur cork trees are either male or female. The fruit is a black, rounded drupe — a fleshy berry containing a seed — about ½ inch in diameter that gives off an unusual odor when bruised. This tree belongs to the citrus family, whose members often have aromatic characteristics. In more humid climates, the species can become invasive, so care is often taken to plant only grafted male cultivars.
Arboretum records do not indicate that this tree is a named cultivar. It is located in a low-traffic area of campus, so it has not yet been determined whether it is a fruiting female. If you observe this trait, please inform the landscaping staff.