We just received this lovely newsletter from Elaine Kingett, who runs several of her "Write it Down" writing retreats here in spring, summer and autumn. You can find out more about them under the Activities tab on this webpage.
I've never heard the Spanish chestnut referred to as the Orgasm Tree, but yes, she is right about the smell of the blossom, that discreet, green starburst of catkins.
The Orgasm Tree