Red horse-chestnut

Aesculus × carnea, or red horse-chestnut, is a medium-sized tree, an artificial hybrid between Ae. hippocastanum (European horse-chestnut) and Ae. pavia (red buckeye). Its exact origin is uncertain, arising in Germany around 1818. It is a popular tree in large gardens and parks, widely planted throughout Europe.

It is a tetraploid plant, arising from autopolyploidy with chromosome doubling of its diploid parent species. The result of this is that it is fertile, producing viable seeds that breed true, the progeny identical or near-identical to the parent tree. It is locally naturalised in England, and more rarely so in Ireland, Scotland, and Wales.