
American Chestnut Burr- Castanea dentata
This is an American chestnut burr. They contain three nuts, which in this case were long gone since I found this burr in spring (they fall off the tree in autumn, after the frost).
Native to eastern North America, American chestnut used to be pretty common until it was devastated during the first half of the 20th century by chestnut blight. Up to 4 billion trees were destroyed as a result. It's now listed as critically endangered.
Habitat: Deciduous forest

The American chestnut is a large, monoecious deciduous tree of the beech family native to eastern North America. Before the species was devastated by the chestnut blight, a fungal disease, it was one of the most important forest trees throughout its range, and was considered the finest chestnut tree in the world. It is estimated that between 3 and 4 billion American chestnut trees were destroyed in the first half of the 20th century by blight after its initial discovery in 1904.