The Friends of the Wild Flower Garden, Inc.

American Chestnut is a large deciduous tree, not native to Minnesota, that before being decimated by Chestnut Blight, was a well formed tree with a towering crown often reaching 100 feet. The tree shown here is being grown as a landscape specimen and shows some deformity. In their native habitat it is mostly shrubby re-sprouts from the old stumps that are found. Work is being done on creating a blight resistant tree - see notes a page bottom.

The bark is smooth and grayish-brown when the tree is young with the trunk developing flat-ridged fissures as it ages.

Twigs are chestnut to orange brown in color, with lighter lenticels, without hair. Buds are the same color with 2 unequal outer scales that cover several smaller inner scales. Terminal buds are absent, instead lateral buds rise from a leaf scar.

Leaves are alternate on the twig, not lobed, but with margins sharply serrate, each tooth triangular, tapering to an awn that is usually more than 2 mm long. The shape is narrowly obovate, with a wedge shaped base, and tapering to a long narrow pointed tip. The upper surface is smooth but the underside has evenly distributed very small embedded glands.

Flowers: The tree is monoecious, that is with separate male and female flowers. Male flowers occur in slender yellow-green 6 to 8 inch hanging catkins from the leaf axils of last year's growth. The male flower usually has 12 stamens surrounding a pistillode (sterile pistil) that has whitish or yellowish hairs. Female flowers are found near the base of the catkins. They occur in sets of 3 in a cup shaped structure called a cupule. Though small, the sepals are distinct and there are 6 carpels and styles.

Seed: The cupule with its 3 flowers after fertilization develops into a 4-valved spiny structure that completely encloses 3 nuts. At maturity the cupule separates along the valve margins. The spines on the cupule are without hair. The nuts obovate in shape and flattened on one or two sides, about 3/4 inch to 1 inch in size. They are sweet and edible.

Habitat: American Chestnut grows in a mixed deciduous forest environment where there is good moisture, well drained soils; full sun is required for a good shape.

Names: The genus name, Castanea, is from the Greek word kastanaion and refers to a similar tree of Southern Europe. The species, dentata, refers to the prominent leaf teeth. The author names for the plant classification are: First to classify was ‘(Marshall)’ which refers to Humphry Marshall (1722-1801), American Botanist, who published in 1785 - Arboreteum Americanum: The American Grove, an Alphabetical Catalogue of Forest Trees and Shrubs, Natives of the American United States. His work was supplemented by "Borkh" which refers to Moritz Balthasar Borkhausen (1760 - 1806). German naturalist and forester. He published several works on forestry and woody plants and was the taxonomic author of the Alliaceae and Asclepiadaceae families.

Other species: The genus Castanea has three species. C. dentata is the most widespread in range while the other two are restricted to only part of that range and their cupules have only 2 valves not 4. C. ozarkensis has long spines on the fruiting cupule, often over 10 mm and the tree bark can be deeply fissured. C. pumila has cupules where the longest spines are usually less than 10mm and the tree bark is usually not fissured, or only shallowly.