Castanea dentata aka American Chestnut

Castanea dentata, also known as the American chestnut, is a large, fast-growing deciduous tree of the beech family. It is native to eastern North America and was once a major component of the Eastern hardwood forest. The American chestnut produces burred fruit with sweet, edible nuts. However, the species was devastated by chestnut blight, a fungal disease that came from Chinese chestnut trees that were introduced into North America from East Asia. It is estimated that the blight killed between 3 and 4 billion American chestnut trees in the first half of the 20th century, beginning in 1904. Today, the species is listed as endangered in the United States and Canada, although many small shoots of the former live trees remain. Several groups are attempting to create blight-resistant American chestnuts. Scientists at the SUNY College of Environmental Science and Forestry created the Darling 58 cultivar of American chestnut by inserting the oxalate oxidase gene from wheat into the genome of an American chestnut, making it resistant to the chestnut blight. As of 2021, the researchers who developed this cultivar are working toward applying for government permission to make these trees available to the public. Alternate approaches to developing a blight-resistant cultivar include cross-breeding among partially blight-resistant American chestnuts or crossbreeding with the moderately blight-resistant Chinese chestnut, then backcrossing with the American chestnut, with the goal of retaining most of its genes. The American chestnut is a large, monoecious deciduous tree with globular spreading crowns. Oblong-lanceolate, toothed, dull green leaves (6-10” long) turn shades of yellow in fall. Aromatic creamy yellow-white male flowers are densely clustered in slender catkins (4-8” long). Female flowers appear in smaller inconspicuous catkins. Blooms in June. Small nuts (hazel nut size) are sweet and edible, and are encased in spiny burrs (2-3” diameter). Although the American chestnut is almost extinct in the wild now, having succumbed to chestnut blight, it persists mostly in the form of sprouts from old stumps and root systems. In addition to its use as a forest tree, American chestnuts have also been grown as houseplants. However, they require regular watering and long-lasting direct light to thrive. They prefer soil that is well draining and do not typically need added fertilizers if they are repotted each time they double in size. American chestnut belongs to the Castanea genus and is native to Eastern Canada to the Northern Central and Eastern United States.