Opposing branches: The branches of the ash tree grow in pairs on opposing side of the twigs. The only other tree species with opposite branching and compound leaves are boxelder (Acer negundo) and Amur corktree (Phellodendron amurense). (F1633, Reviewed Jan. 2019) Ash trees (in the genus Fraxinus) are susceptible to attack by the emerald ash borer (EAB), a non-native insect. Leaflets are shiny and the fruit is distinctly different from ash. Is it an ash tree? However, individual ash trees have different genders and only female trees produce fruits. While other woody plants, such as mountainash and pricklyash, have “ash” in their name, they are not true ash, or Fraxinus species. Land Grant. To properly identify ash trees, use the following criteria: Branch and Bud Arrangement. Boxelder has opposite branching and compound leaves, but the leaves have only three to five leaflets. In seed clusters, seeds always occur in pairs instead of singly. In a good year, a tree produces many thousands of them. Site Development: Digital Strategies (Division of Communications) Most varieties of ash trees generally grow to between 50 and 80 ft. (15 – 24 m). Accessibility information.  X Research source Boxelde… Here’s what to look for: Ash trees have buds and branches directly across from each other, compound leaves with 5 to 11 leaflets, and diamond shaped ridges on the bark of mature trees. Leaflet margins are serrated and leaflets are opposite each other, except for the single leaflet at the tip. Branches and buds are … Vanderbilt University is committed to principles of equal opportunity and affirmative action. Buds and branches normally are found directly across from each other and not alternating along the stem. If a tree is a male, you will never see fruit on it. Ash Tree Identification. Only true ash are susceptible to attack by emerald ash borer. Identification starts with making sure that the tree in question is a true ash. However, corktree leaves may contain as many as 13 leaflets. Ash trees have compound leaves, composed of five to 11 leaflets. Student Focused. Feel free to use and share this content, but please do so under the conditions of our. The compound leaves of black walnut contain nine to 15 leaflets, but the leaves occur in alternate placement on the branches. A particular female tree may produce fruit abundantly one year and produce almost no fruit the next year. There are 65 species of ash trees, with 18 varieties of ash being native to North America. How to Identify an Ash Tree Once people understand the characteristics of an ash tree, they can often identify one by simply glancing at it. Black Ash (Fraxinus nigra) The wood structure of black ash makes it a great choice for weaving, as … Research Institution. Black ash (F. nigra) is native to a very small portion of northeastern North Dakota but sometimes is planted in urban areas as an ornamental. Note, however, that buds and branches may die; therefore, not every branch will have an opposite counterpart. Determining the variety you have is a process of elimination. The most common ash trees planted in the landscape are white ash(Fraxinus americana) and green ash(Fraxinus pennsylvanica). Fruits are large nuts contained in green husks that turn black in late fall. Mountain-ash and prickly-ash are not true ash species and are not susceptible to EAB. So if you see the characteri… Individual seeds are held in samaras that each have a single wing. Mountain-ash flowers occur as creamy white clusters in early spring; fruits are red-orange berries. In North Dakota, green ash (Fraxinus pennsylvanica) is extremely common in native woodlands, shelterbelts and urban forests. On young trees, bark is relatively smooth and may have an orange cast. As trees age, the bark becomes gray and develops diamond-shaped ridges. Like ash, corktree has compound leaves that are arranged opposite on the twigs. Other native ash trees less commonly found include black ash(Fraxinus nigra) and blue ash(Fraxinus quadangulata) (not shown). Also, the amount of fruit produced from year to year varies. Ash trees (in the genus Fraxinus) are susceptible to attack by the emerald ash borer (EAB), a non-native insect. Illustrated key to common trees of middle Tennessee, Creative Commons Attribution-NonCommercial-ShareAlike license, Site Development: Digital Strategies (Division of Communications). The first step in determining if a tree has been infested with EAB is to make certain that it is an ash tree. Green and white ash are the most commonly found ash species in the Midwest with blue ash being rare. The first step in determining if a tree has been infested with EAB is to make certain that it is an ash tree. View whether the branches have opposite branching. Some people refer to them as mate branches. The medium-sized trees have a spreading round canopy up to 50 ft. (15 m) wide. The twigs of boxelder trees often are blue/purple with a white, waxy covering. Ash trees are large canopy trees that are in the tree genus Fraxinus and family Oleaceae. This tree rarely is planted in North Dakota; it’s found only in a few landscapes. the Vanderbilt Arboretum Emerald Ash Borer web page. The winged fruits of ash trees are unmistakable. Other trees have alternate branching, with branches alternating left and right as they grow from the main branch. White ash (F. americana) rarely is found in urban plantings and is not native. Leaves of mountain-ash are compound, but the leaves have alternate placement on the branches. All rights reserved. Vanderbilt®, Vanderbilt University®, V Oak Leaf Design®, Star V Design® and Anchor Down® are trademarks of The Vanderbilt University. This means that branches originate from the same point when they extend from the main branch. Seeds occur in clusters that may stay on the tree well into winter.