Aesculus hippocastanum

Aesculus hippocastanum, the horse chestnut, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is a large deciduous, synoecious tree. It is also called horse-chestnut, European horsechestnut, buckeye, and conker tree. It is sometimes called Spanish chestnut. This name is typically used for Castanea sativa.