Identifying American Chestnut Trees
This page is designed to help you distinguish among several species of the chestnut family (Castanea) commonly seen in North America. Also included are three non-chestnut species that are often confused with chestnut. Click on the names below to see examples and characteristics of the common species of chestnut or chestnut look-alikes.
Overview of the Five Species
A good place to start is to compare American and Chinese chestnuts. Over 80% of the leaves that are sent to us each year for identification are either from Chinese chestnuts or Chinese/American hybrids, because these trees are resistant to the chestnut blight. Also compare true American chestnut with three trees often confused with chestnut: chestnut oak, beech, and horse chestnut.
How to Have Your Chestnut Tree Identified
Chestnut tree identification is a free service that TACF provides to the public. A good leaf and twig sample is the best way to identify your tree, as photos alone can be misleading and do not allow for a definitive identification.
- If you think you have an American chestnut tree, send us a freshly-cut 6-12 inch twig with mature leaves attached. Leaves should be from sunny exposure, if possible.
- Spring or Summer is the best time to collect samples for identification purposes. Samples submitted after November are discouraged because dry leaves are more difficult to identify correctly.
- Press leaves between pieces of cardboard to flatten and prevent curling or crushing as they dry. Crushed or bent leaves are much harder to analyze. See How to Make A Plant Press
- To prevent mold and material deterioration, do not put the sample into a plastic bag.
- Please do not send burs. If you want to send nuts to assist with the sample identification process, remove the nuts from the bur first.
Tree Locator Form
Please download, fill out, and include this Tree Locator Form with all submissions for leaf sample identification.
You will find the mailing address for your sample on the second page of the form.
- Print and fill-out the Tree Locator Form so that we can keep track of your sample and send you results. This form is vital for our inventory of wild trees, so please include latitude and longitude as well as good contact details. A GPS app called TreeSnap will automatically determine this for you.
- Please do not send or email photos without mailing in a leaf sample as well. Photos can assist with the identification process, but precise identification cannot be made using photos alone.
- You will get your results via email. Results can take up to 12 weeks, sometimes longer, especially during Fall when our regional science coordinators are focused on harvest season. Please be sure to check the spam folder in your email account for results.
Sample Identification Process
Scientists look at the morphological traits of the sample for identification, which is a good but not exact science. The macroscopic traits include: thickness, shape, luster, and dentation of the leaf; angle of the leaf base; shape, color, and hairiness of buds; presence and shape of stipules; color, hairiness, and relative thickness of stem; and character of lenticels – in addition to the leaf hairs on the underside of the leaf.
A typical American chestnut has a thin, canoe-shaped leaf with a dull leaf surface and hooked or breaking ocean wave dentation. Buds are often red or orange, smooth, and pyramidal in shape, protruding from the stem at a 45-degree angle. Stipules are narrow when present.
How Are Sampled Trees Used?
Once a sample is identified, the submitter is contacted with an ID report and data about the tree they sampled is entered into our dentataBase database, which adds to our ever-growing inventory of wild trees existing in the landscape. If the sampled tree may be of use to our program, the local chapter is alerted and invited to reach out to the submitter or landowner to discuss potential next steps.
In recent years, much of our chapter work has been focused on germplasm conservation, and flowering wild American chestnuts have been the primary interest for trees submitted through our ID program. These trees may be candidates for harvesting open-pollinated seed, or for planning of controlled pollinations. Nuts from these wild trees are then planted in germplasm conservation orchards or used in other ways to support our programs.
Samples have also been used to identify areas of the native range with greater genetic diversity or less representation, which we then apply to scientific projects to further the reforestation of the American chestnut to its native range.