A genus, Aesculus, of deciduous trees or shrubs belonging to the plant order Sapindales. Buckeyes grow in North America, southeast Europe, and eastern Asia to India. The distinctive features are opposite, palmately compound leaves and a large fruit having a firm outer coat and containing usually one large seed with a conspicuous hilum. The Ohio buckeye (A. glabra), a small tree which may grow to a height of 30 ft (9 m), is found mainly in the Ohio valley and in the southern Appalachians. It can be recognized by the glabrous winter buds, prickly fruits 1–2 in. (2.5–5 cm) long, and compound leaves having five leaflets.