Family Hippocastanaceae, composed of the buckeyes and the horse chestnuts (genus Aesculus), native to the northern temperate zone. The best-known species of horse chestnut is the common, or European, horse chestnut (A. hippocastanum), native to southeastern Europe but widely cultivated as a large shade and street tree. The Champs-Élysées in Paris is lined with rows of horse-chestnut trees