Green Ash
Arbor walk #23, Treekeeper ID #2384
This native tree species is threatened by the Emerald Ash Borer. Since its discovery in 2002, the Borer, a native of Asia, has killed hundreds of millions of ash trees in North America. Washington University is monitoring the health of ash trees and is treating a select few to prevent depletion of the species from the campus forest.
This tree is widely used for ornamental purposes, and is the most widely planted tree of the American Ashes. One of the most distinguishing features of the Green Ash is its anastomosing bark. Although the Green Ash bears great similarity to the White Ash, they can be distinguished by examining their leaf scars and lower leaf surfaces.
| Common Name | Green Ash |
|---|---|
| Latin Name | Fraxinus pennsylvanica |
| Indigenous Name(s) | |
| Cultivar/Variety | |
| Commercial Name |
Global Distribution
GPS Coordinates
N/A
Percent Concrete
N/A
Distance to Buildings
| Year | Close Building #1 | Close Building #2 | Close Building #3 |
|---|---|---|---|
| 2020 | Mallinckrodt, 9.41 m | Graham Chapel, 30.40 m | Busch Laboratory, 24.37 m |
Distance to Other Species
| Year | Close Species #1 | Close Species # 2 | Close Species # 3 |
|---|---|---|---|
| 2020 | Flowering Dogwood, 11.30 m | Eastern Red Cedar, 11.75 m | Eastern Red Cedar, 11.60 m |
Standard Measurements
| Year | Height (m) | DBH (cm) | Caliper (m) | Crown Diameter N-S (m) | Crown Diameter E-W (m) | Average Crown Diameter (m) |
|---|---|---|---|---|---|---|
| 2020 | 19.8286 | 83.44 | N/A | 19.64 | 21.78 | 20.71 |
| 2023 | 18.41 | 85 | N/A | 21.94 | 20.17 | 21.055 |
| 2024 | 24.17 | 87.8 | N/A | 20.8 | 19.71 | 20.255 |
Nests and Pests
| Year | Description |
|---|---|
| 2020 | 2 squirrel nests 1 songbird nest |
Leaf Identification
The leaves of the Green Ash are pinnately compund with lance-shaped leaflets. They are a dark green and turn yellow in the fall.
Twig and Bud Identification
The twig is light green-gray with scattered small white lenticels (pores). Leaves are arranged oppositely on the twig (each leaf is attached to the stem opposite another leaf). The bud is small, pointed, and colored similar to the twig.
Bark Identification
The Green Ash has gray bark with a unique diamond-shaped pattern of deep ridges.
Fruit Identification
The Green Ash has a samara (thin, winged seed pod) as a fruit; however, these samaras are not winged. Rather, they are long, thin, light green strips that contain the seed inside. They ripen in the fall.
[photo forthcoming]
Flower Identification
The flowers of the Green Ash are green. The male and female flowers are dioecious (in clusters on separate trees). The male flowers are yellow-green finger-like projections that turn purple at their tips. These flowers have no petals. The female flowers are tiny, green, and become the fruits when fertilized. Both flower in mid-spring.
[photo forthcoming]
