A type of tree which, during the spring season, gives off an odor similar to that of semen.
When I was walking outside the other day, I thought someone must have shot an enormous load nearby, but it was only the cum trees!
Any tree that, when in bloom, gives off a pungent odor of of semen so strong that it feels that nature has blown a load up your nose.
Ashley: Damn, the smell of that cum tree reminds me of a money shot that went up the nose!
Mary: I seriously thought I was the only person who ever noticed that...