Buckeyes--or horse-chestnuts, as they are known in Europe--are not terribly common in urban parts of the Sacramento valley. Best known is our native California buckeye, Aesculus californica, which, while beautiful, makes a poor shade tree. Unlike almost every other local tree, it grows its leaves in the winter and sheds them in summer. A few more species can be seen here and there, but they are not popular, perhaps because of their large nuts, known as conkers. Still, their flowers can be dazzling, and all of the species I have seen grow at least adequately here, so perhaps it is worth trying them more often.