The white flowering trees are doing their thing, which is pretty to see and horrible to smell. The odor they emit is odd. Think of the tree’s nickname: Tuna on a Trunk. It’s not pleasant.
Why would a flower smell so bad?
It might be to attract flies. The flowers bloom so early in the spring that bees are not common. Flies visiting the flowers can be pollinators. The scent also might discourage critters from eating the blooms.
And why are there so many of these stinky trees in yards and landscapes? They are tough trees. They’re commonly planted in hell strips. They thrive right next to asphalt and have few insect or disease problems.
The flowers don’t last long. You only have to hold your nose for a couple of weeks.
P.S. They rarely produce pears and when they do, they’re not the kind we eat