American Chestnut
Arbor Walk #111, Treekeeper ID #6353
The American Chestnut is a historically and cuturally important tree that unfortunately has a sad story. This species used to be one of the biggest and most numerous trees in the Eastern United States, but it is now functionally extinct. In the early 1900’s, the parasitic fungus Cryphonectria parasitica was accidentally introduced to America and caused what we now call the Chestnut Blight. In about 50 years, this pathogen virtually decimated the entire American Chestnut population. This species is not considered truly extinct because the fungus is only able to kill the aboveground portion of the tree, keeping the root system alive. The roots continuously grow new sprouts just to be reinfected in adolescence, a process that continues to repeat as long as the tree has a root system strong enough to keep sprouting.
Many efforts are going into trying to restore the tree’s population to its former dominance. The three main strategies used are breeding blight-resistant cultivars, incorporating biotechnology to keep them from being infected, and biocontrol, which attempts to use living organisms to control the pathogen. Arbor Walk #111 and other Washington University American Chestnuts all use one of these techniques to hopefully grow mature trees.
| Common Name(s) | American Chestnut |
|---|---|
| Latin Name | Castanea dentata |
| Indigenous Name(s) | Miami: maamišimiši |
| 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 |
|---|---|---|---|
Distance to Other Species
| Year | Close Species #1 | Close Species # 2 | Close Species # 3 |
|---|---|---|---|
Standard Measurements
| Year | Height (m) | DBH (cm) | Crown Diameter N-S (m) | Crown Diameter E-W (m) | Average Crown Diameter (m) |
|---|---|---|---|---|---|
| 2023 | 2.16 | 1.187 | 0.88 | 0.85 | 0.865 |
Nests and Pests
| Year | Description |
|---|---|
Leaf Identification
The leaves of the American Chestnut are 5″ to 9″ long with an elliptic (tapers consistently at both stem and tip) shape and pinnate veins. They are coarsely toothed, each tooth with a bristle at its tip. The top surface is typically yellow-green while the underside is paler. The leaf underside has sparse hairs along the midvein, unlike some hairier related species. The entire leaf is glabrous (smooth).
Twig and Bud Identification
The American Chestnut twigs are orange-brown and have numerous small lenticels (pale pocked marks). The buds are also orange-brown and are usually 1/4″ long with multiple scales. The buds and twigs are glabrous.
Bark Identification
When young the bark is smooth with green to a chestnut-brown color. With age, it develops large interlacing ridges and furrows. If the tree is infected with blight, the bark will be sunken and split. Orange fungal bodies are often growing out of these splits.
Fruit Identification
The fruit of the American Chestnut have large, spiny husks covering 2 or 3 nuts. These husks are round and about 2″ to 2 1/2″ in diameter. The nuts are edible, but the husk is very sharp.
Flower Identification
The American Chestnut is monoecious. The male flowers are white and occur along 6″ to 8″ long catkins, and the female flowers are also white and found at or near the base of the catkins. The flowers have a musty odor, sometimes described as fishy.
ID Tips
- Compared to the Chinese Chestnut, the American Chestnut has longer leaves with larger acute bristles, darker twigs, and fuzzier nuts.
- The bristles of European Chestnuts are more triangular than the clawed bristles of the American Chestnut
- Asian Chestnut species have leaves which are much darker and glossier than the American Chestnut, whose leaves are thinner and a medium shade of green.
