Wednesday, January 6, 2016
Meet the Green/Red Ash - Fraxinus Pennsylvannica
The "Green or Red Ash" - (Fraxinus Pennsylvannica) is a medium to large, deciduous tree that is native to Eastern/Central North America. This range begins in Nova Scotia, Alberta and Western Colorado in the North and continues through Texas in the Southwest and Nothern Florida in the Southeast. It has slowly becoming naturalized in many parts of the Western United States and Central Europe. It grows in a Oval or Upright form.
Ash varieties are known to frequently cross or hybridize with one another sometimes causing much confusion with experts trying to positively identify a species. Botanists have recorded that Red and Green Ash were in fact two different species at one time but have completely hybridized to no longer have any unique or differentiating features. The Green/Red Ash are the most widely distributed of all of the American Ashes. Fraxinus Pennsylvannica is a member of the Oleaceae family which also includes Olive, Lilac, Jasmine and Forsythia - all of which are woody trees or shrubs.
Image Citation: T. Davis Sydnor, The Ohio State University, Bugwood.org
When young the bark is smooth and gray, becoming thick and fissured with age. The pinnately compound leaves contain leaflets which range in number from five to eleven, but usually contain seven to nine. The underside of the leaves are hairy, which is a feature that is unique to only this species of Ash. Each leaflet ranges in size from 2-8 inches long and 1/2 - 3 inches wide. The leaves are green in color both above and below, changing to a golden yellow in the fall. Fall coloring usually begins to occur beginning in early September depending on the hardiness zone and weather patterns. Flowers appear in the Spring usually around the same time as the leaves, they occur in very compact panicles. The flowers are small and inconspicuous with no visable petals and are wind pollinated. The fruit or samara is 1-3 inches long, each contains a single seed with an attached elongated apical wing. Winter buds are velvety in texture and red-brown in color. Large annual seed crops provide a good food source for wildlife and birds such as Cardinals, Finches, and Wood Ducks.
Image Citation: Karan A. Rawlins, University of Georgia, Bugwood.org
Green/Red Ash numbers have been greatly impacted by the spread of the Emerald Ash Borer. The Emerald Ash Borer is a small beetle that was introduced accidentally from Asia, these varieties of Ash trees have zero resistance to this pest which has led to devastating results. Prior to the introduction of Emerald Ash Borer, Green/ Red Ash were used extensively as an ornamental or street to replace many American Elms (which were almost completely lost between 1950-1960 from Dutch Elm Disease) this high volume of plantings actually facilitated the spread of the borer as they had plenty of trees to feed on and infest. Many cities have learned from the high volume of loss, not just the Elms but the Ash as well, most now replant lost or damaged trees with a variety of species to prevent such widespread damage/loss should another disease or insect pose a future risk.