We finally leave the great genus Acer, maples, and move on to Aesculus, the horse-chestnuts and buck-eyes. This is an old and rather primitive genus of trees and shrubs which has a scattered distribution throughout temperate regions of the northern hemisphere, although the greatest diversity is found in north America. Species are known for their beautiful, insect pollinated flowers borne in vertical racemes, and the fruits which contain one or two very large seeds ('conkers', or 'buck-eyes'). On the whole the genus is not noted for its autumn colour, but Aesculus flava, the Sweet Buckeye, pictured above, turns a lovely orange in the fall. It is native to the SE USA, but here is pictured at Kew, UK. It can grow to quite a large tree and has yellowish flowers.