Mature green ash bark has many ridges and furrows and often has a yellowish tint. Stems will be smooth and have terminal buds (buds at the end) that look like a Phillip’s head screwdriver.
Plant of the Month: Green ash
chase.bergeson • July 14, 2023
Green ash (Fraxinus pennsylvanica)
Green ash (Fraxinus pennsylvanica) is the plant that we have recorded the most times at our wetland monitoring sites. We see many of its saplings at our site as well as mature trees. So how could it be in danger?
Green ash is on the International Union for Conservation of Nature’s (IUCN) Red List as critically endangered due to its vulnerability to an invasive Asian beetle: the emerald ash borer. In NC, white ash, pumpkin ash, and Carolina ash are also vulnerable. This beetle lays its eggs on ash trees and larval emerald ash borers will feed on the tree, killing it, before flying to infest new trees. They have been responsible for the deaths of millions of trees and are likely to continue spreading. Human transportation of ash lumber, including firewood, has accelerated the spread of the emerald ash borer. There are some strategies for protecting trees, including cutting and burning infected trees to stop the spread and introducing predatory wasps. There is also promising evidence that some ash trees may show resistance to the beetle. However, it is likely that ash tree populations will continue to decline. You can find the extent of the emerald ash borer in North Carolina here. For more information: http://www.ncforestservice.gov/forest_health/fh_eabfaq.htm
Green ash is a Facultative Wetland (FACW) plant in the Piedmont and the Coastal Plain, meaning you are more likely to find it in a wetland than in an upland. It makes sense why we see so many at our wetland sites.
In summertime, a great way to identify many trees is by their leaves. What do you think of when you picture a leaf? How many leaves do you see pictured below?
One big leaf! Many Leaflets
Photo By: Alexander Rumpel
One leaf- 3 leaflets
Photo By: Lucie Baret
One leaf!
Photo By: beepboop
Each picture is of one leaf! The leaf is the part of the plant that connects to the stem at a leaf bud. Ash trees have compound leaves, which means that their leaves have multiple leaflets- which do not connect at leaf buds but are part of the leaf as a whole. Young green ash saplings may not have compound leaves.
Green ash leaflets are oval or lance shaped and toothed. They have a light green underside.

Just like red maples (Acer Rubrum), ash trees are one of the few trees that have opposite branching, meaning that one branch should always have a twin growing at 180 degrees from it. Of course, in the life of the tree one of the branches might fall off or be damaged, so always check for any opposite branching on the tree. If you can look closely, you might see a scar on the tree where you would expect to see a branch, indicating that there used to be one present.
Leaf
Photo By: Miles Panych
Leaf underside
Photo By: Miles Panych
Opposite branching and leaf buds
Photo By: James Mickley
Green ash trees may be confused for Carolina ash trees, but are often difficult to distinguish without the presence of its fruits (samaras). Green ash samaras are thin and pointy, while Carolina ash samaras are rounder. Although we currently conduct our vegetation surveys in summer, we can verify our identifications by returning in the Fall and winter and looking for fruits. The nice thing about iNaturalist is we can always go back and change our IDs, if necessary.
green ash friuts
Photo By: cbarron
Carolina ash friuts
Photo By: VTforester
For more plant resources checkout this guide on wetland plants:
https://www.ncwetlands.org/plantguide/
And useful keys through the herbarium: https://herbarium.ncsu.edu/keysetc.htm
Don't forget to check out our our iNaturalist page to see all the plants we've found so far!
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A Decade of Celebrating Carolina's Wetland Treasures
On September 9, 2026, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers issued a supplemental notice of proposed rulemaking (SNPRM) offering additional ways to define “waters of the United States” (WOTUS). Why this definition matters The WOTUS definition determines which water bodies the federal government can protect under the Clean Water Act. In November 2025, the agencies proposed revisions to bring the definition in line with the Supreme Court’s 2023 decision in Sackett v. EPA. After taking public comments, they have now put forward further options. The new proposal narrows federal jurisdiction even more, potentially stripping protections from the vast majority of U.S. wetlands and seasonal streams. What our comment letter says The Carolina Wetlands Association is submitting comments opposing the proposal. Our main concerns: It would undermine the Clean Water Act’s purpose. The law’s goal is to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. This proposal would severely undercut that goal. The “days of water” test is a poor measure. The proposal decides jurisdiction by how many days a year water is present. That number correlates poorly with a waterway’s ability to carry pollution downstream to the rivers, lakes, and estuaries that would stay protected. Streams dry for as few as 30 days a year could lose protection, and polluters would have an incentive to discharge into them rather than into protected waters. Drinking water is at risk. About 56% of North Carolina’s stream miles feeding public drinking water systems are intermittent, ephemeral, or headwater streams. In South Carolina the figure is 51%. These systems serve 6.6 million people, who would bear higher health risks and treatment costs. Wetlands do critical work. They filter pollutants and nutrients that cause algal blooms, dead zones, and fish kills. Losing that function would also degrade groundwater, which many people drink untreated. The legal reasoning is flawed. We argue the agencies misread the Supreme Court’s language. “Relatively permanent” describes geographic features such as streams with defined beds and banks. The word “continuously” modifies “flowing” and doesn’t limit what counts as relatively permanent. It would be hard to implement. Many affected streams have no data showing how many days they lack surface water. That makes the rule difficult for agencies to administer and leaves landowners unable to tell whether the Clean Water Act applies to their property. The impacts haven’t been analyzed. The agencies should not finalize a rule before measuring the added pollution flowing from newly unprotected waters into those that supply drinking water, or projecting the resulting damage to downstream uses. What you can do Read the SNPRM Submit your comment by October 9, 2026, under Docket ID No. EPA–HQ–OW-2025-0322 . Personal stories about the streams, wetlands, and drinking water you depend on are especially effective. Learn more: read the comments we submitted on the November 2025 version of the rule, many of which still apply.
Welcoming New Members to the Carolina Wetlands Association Board