Oregon ash (Fraxinus latifolia) is a medium tree in Oregon, growing to 25 meters tall. It has shorter branches and oppositely arranged, deciduous leaves, with five to seven leaflets pinnately venated and compound. Leaflets can be 13 centimeters long, olive-green and oval, with a paler color underneath. It can be found south of British Columbia to the Sierra Nevada range in central California. The Oregon ash is susceptible to showing signs of rot and disease, even if its not actually present. The tree is susceptible to the disease Sudden Oak Death and butt rot. It produces winged seeds, three to five centimeters long. They disperse with the wind, and the wings slow down the rate of acceleration greatly, allowing it to cover a greater area of dispersal. It prefers loose and damp soils.