Horse Chest Nut.

Have you ever wondered why Aesculus hippocastanum is known as the Horse Chestnut tree?

The upright candle like flowers appear every spring, creating a spectacular display

and later in the year produce the spiky fruits which contain the nut, or conker as they are known in the UK.

Before modern veterinary medicines, these nuts were ground and fed to horses to cure respiratory illness, which maybe the reason for the name, 

but I like the second possible reason. When the leaves abscise from the tree, what remains is a leaf scar which resembles a horse shoe.