Our White Ash tree, scientifically known as Fraxinus americana, is located at the edge of Bayne Park along North Balph Avenue near the World War Monument. Look for a tree with opposite branching.
On most trees, branches and leaves form alternately so they are not directly across form each other. Ash trees have branches and leaves that form directly opposite of each other, which you can see in the image above.
MADCap Horse is a helpful mnemonic device to remember which trees and shrubs typically have opposite branching. [M=Maple] [A=Ash] [D=Dogwood] [Cap=Caprifoliaceae family which consists mostly of shrubs and vines] [Horse=Horse Chestnut and Buckeyes]
The White Ash tree has compound leaves, as do our Horse Chestnut trees. The compound leaves, as shown in the botanical illustration, consist of seven to nine leaflets.
Each leaflet has a finely toothed edge and tapers to a pointed tip. The leaflets are matte green above and lighter green below.
The male and female flowers are borne on separate trees, opening in May typically just before the leaves appear. Both types of flowers lack petals, which is advantageous as wind can more easily move the pollen without the obstruction of petals. The female flowers form in looser clusters, and once pollinated they produce samaras with a shape resembling the end of a canoe paddle, as shown in the image below by Keith Kanoti.
The samaras range from one to two inches long, usually containing just one seed. They dangle in clusters and typically hang on the tree until late Autumn, when a majority of obstructive leaves have dropped. Flying aloft in the wind, the winged samaras ultimately disperse the seeds up to hundreds of feet from the tree.
White Ash trees are dioecious, which means each tree is either male or female. If you encounter a White Ash tree and find no evidence of samaras from Summer through Autumn, either none of the female tree’s flowers were pollinated, or the tree is a male and it does not produce samaras. Our tree in Bayne Park is likely a male tree.
Ash bark on older trees features a distinct pattern of interlacing diamond-shaped ridges, while younger trees exhibit smoother bark. The common name Ash comes from the ash-grey color of the bark. You may notice the bark of our White Ash tree has a greenish-yellow tinge.
You are seeing lichen which is attached to the tree. Lichen is a symbiotic relationship between algae and fungi, and does not damage the tree. This particular species is named lemon lichen, because it ranges from lemon yellow to greenish-yellow in color. It is very small with minute lobes that can be be viewed more easily through a hand lens. This species is known to grow the softer bark of Ash, Walnut, and Maple.
Ash trees are prone to develop multiple trunks which must be removed for proper tree development. One of the trunks was removed from our Bayne Park specimen.
White Ash tree leaves can turn a variety of rich shades ranging from purple, red, yellow, and green in the Autumn. Interestingly, on occasion all of the various hues can be displayed on the same tree.
Look closely to see the exuviae evidence that proves there was once a cicada on our White Ash tree in Bayne Park, only the exoskeleton made of chitin remains. Previously, a wingless cicada nymph crawled out of the soil to ascend the craggy bark. When its exoskeleton split open along the back, the cicada emerged as a winged adult.
There are many insects that can be found in and around ash trees. In the book Songs of Trees the author, David George Haskell, came across a giant ash tree that had just fallen and was full of banded ash borer beetles. He vividly describes the action of the beetles: “Their every footfall is a dry splinter of sound. Six thousand chitinous feet raise a shudder of air, a scrabble of bark. The insects wrestle, they mate. Slaps punctuate their writhing as clumps drop to the leaf litter. Grounded, on they fight, then break apart and fly arcs to the tree, wings zizzing. Wasped in black and yellow, with tendrilous antennae, they are fearless as I approach. Their dissembling countenance protects them: even though the insects are beetles, the color of their bodies, their confident behavior, and the sound of their wings are hornetlike.”
Fortunately the banded ash borer beetles only use dead and freshly-downed ash trees as their nursery, so our still-standing live White Ash tree is safe from them- for now.
However, there is a destructive beetle that does attack living White Ash trees- the emerald ash borer, which is shown above. You may have heard of this infamous invasive beetle’s negative impact on the environment and economy because these small beetles are collectively responsible for millions of recently dead and dying ash trees.
During their larval stage, the emerald ash borers feed on sapwood just inside the bark of living ash trees, creating extensive tunnels that disrupt conductive vessels that move water and nutrients through the tree. This results in devastating canopy die-back, with progressively larger branches becoming brittle and falling.
The White Ash tree is valuable to wildlife, finches and cardinals dine upon the seeds and older trees often form cavities that provide nesting sites for woodpeckers, nuthatches, owls, and squirrels.
White ash wood is the most valuable of the North American ash species and is used to create baseball bats, hockey sticks, polo mallets, tool handles, canoe paddles, snowshoes, church pews, veneer, doors, and furniture.
The Morgan Motor Company, located in the town of Malvern in the countryside of England, uses Ash wood to create car frames because it is lightweight, durable, incredibly flexible to work with, and also provides effective vibration dampening.
Sweet Spot: 125 Years of Baseball and the Louisville Slugger by David Magee is a comprehensive history of the Louisville Slugger baseball bat. White Ash trees became part of baseball fame when Louisville Slugger started using the wood to make bats. Read this book to learn all about the impact of the White Ash tree on one of America’s favorite pastimes!
Trees of Pennsylvania: Field Guide by Stan Tekiela features over a hundred of trees that are found in Pennsylvania and is full of facts.
If you are curious about the lichen that you see on the bark of trees and rocks, Lichens of North America by Irwin M. Brodo is a large comprehensive guidebook focused on lichens of the North America with spectacular color photographs, descriptions, identification keys, and distribution maps.
The Pests that Girdle the Home of Tucker the Turtle by Cynthia Sandeno is a fascinating book that makes the concept of invasive species interesting and easily understandable for children. Tucker, an Eastern box turtle, shares his experiences with twenty-four different invasive species including the emerald ash borer that attacks White Ash trees.
Learn more about all the Trees of Bayne Park and explore our Interactive Bayne Park Tree Map to see the locations, photographs, and names of over a dozen different species of trees. Be sure to also visit our Treesources page to lean about local trees, caring for trees, and more.
This post written by Linda, 8/18/20