The horse chestnut is a fairly large tree, usually growing 50-75 feet tall, but capable of reaching heights over 100 feet. The leaves of Aesculus hippocastanum are opposite and palmately compound with 5 or more leaflets. The only other tree of that description in Wisconsin is Aesculus glabra. The buds of A. hippocastanum are conspicuously sticky and those of A. glabra are not, the flowers are white as opposed to yellow in A. glabra and the leaflets are conspicuously different in shape. The fruits in both species are large spiny, green capsules, each containing 1, or more, large shiny brown seeds. It is tolerant of many soil types, as long as it has adequate moisture, though it grows better in locations that are not windy. It tends to have weak limbs, causing it to easily break branches under heavy ice or snow loads. This tree is found primarily in the eastern United States and Canada, though it can also be found along the western coast where it has been purposefully planted as a part of maintained landscapes.
Horsechestnut: A Poisonous Plant to Horses, http://www.understanding-horse-nutrition.com/horsechestnut.html (accessed January 26, 2017).
Trees of Wisconsin: Aesculus hippocastanum, horse chestnut, http://www.uwgb.edu/biodiversity/herbarium/trees/aeship01.htm (accessed January 26, 2017).