The Horsechestnut's botanical name is Aesculus hippocastanum. Apparently, Aesculus was a name to imply that the tree was oak-like, but the acorns were edible. Hippo- is Latin for horse and -astanum refers to a chestnut itself (the genus for regular chestnuts is Castanea). The species name was applied to this tree because horses were historically fed the chestnuts of this species to keep their coats shiny. I'm told that us humans don't have much appreciation for the nut, which is good, since in high enough quantities, the fruit is toxic.
Central Park is loaded with Horsechestnuts, though there are few that are planted with enough space that you can stand a hundred feet away from the tree and appreciate its silhouette. Not so with this lovely specimen. That, plus the fact that it was blooming, plus the fact that it was next to such a sweet Victorian home, compelled me to get a good photo of it.
Naturally, no sooner than I write the above, I stumble on this Horsechestnut in Central Park:
So, nevermind what I said previously! Here's a close up of the flowers:
I love how showy the stamens are and hadn't really appreciated the fragrance from these before. It's quite perfumey, more than I had imagined.