Horse chestnut is a member of the maple or soapberry family that is
native to southeastern Europe and cultivated elsewhere to provide shade
in parks and along sidewalks. The tree is also known as the conker tree
and buckeye, although it shouldn’t be confused with either California
buckeye or Ohio buckeye, which are unrelated. In addition, despite its
common name, horse chestnut “conkers” or nuts are poisonous to horses.
Historically, and currently in Europe, horse chestnut is used to
counter venous insufficiency and inflammation. Horse chestnut extract,
prepared from the conkers, is also found in Bach flower remedies. The
conkers contain a number of active compounds, including quercetrin,
scopoletin and aesculetin, as well as the plant sterols sitosterol,
stigmasterol and campesterol.