Fraxinus is a genus of flowering trees and shrubs commonly known as ash, with species native to North America, Europe, Asia, and Africa. It belongs to the Oleaceae family, which includes olive and lilac plants. Fraxinus is threatened by the emerald ash borer, a boring beetle native to Asia and invasive in the United States, and by some species of caterpillar. Fraxinus produces strong but elastic hardwood with many important uses.
The wood of Fraxinus plants is commonly used to make tools, bows, cricket and baseball bats, and guitar bodies. It is a popular veneer on office furniture and flooring, but is not suited for outdoor use, since the darker, interior heartwood does not tolerate prolonged contact with the ground. Fraxinus is also a popular decorative tree, and it makes an excellent firewood. The bark of the ash tree is used in Traditional Chinese Medicine (TCM) for diarrhea, vaginal discharge, and redness or swelling of the eyes.
Native Americans of eastern Canada and the northeastern United States traditionally made baskets out of the black ash tree (F. nigra). Early European settlers to the present day United States used the heartwood of the native blue ash (F. quadrangulata) to make blue dye. The white ash or American ash (F. americana) and the green ash or red ash (F. pennsylvanica) of Eastern North America are among the most popular Fraxinus species for decorative use and for their wood. Western North American ash species include the chaparral single-leaf ash (F. anomala), the California ash (F. dipetala), the Oregon ash (F. latifolia), and the Texas ash (F. texensis).
The narrow-leafed or Caucasian ash (F. angustifolia) and the manna ash (F. ornus) are both native to parts of Europe, northwest Africa, and southwest Asia. In the Middle Ages, Europeans used the sugary sap of these trees, which they called manna after the biblical food provided by God to the Israelites during their travels in the dessert. Another European and southwest Asian ash tree is the common ash or European ash (F. excelsior), and another ash tree native to northern Africa is (F. dimorpha). Asian Fraxinus plants include Japanese ash (F. lanuginosa) and Manchurian ash, or Chinese oak,(F. mandschurica).