By Phran Novelli

PHILADELPHIA (CBS) – If you’re starting to sneeze, look up in the trees. Way up. Higher. Many trees that cause allergies are the tall ones with flowers high in the sky – they’re too tiny and far away to see with your eye, but their pollen finds you.

Most of the bigger, pretty flowers we see on trees closer to the ground each spring – like cherries, dogwoods, crabapples and magnolias – are pollinated by beetles, bees, birds or bats – so they have stickier pollen that stays put, it clings to the flowers, waiting for critters to come collect it.

But other trees, like our towering oaks, are pollinated by the wind. They have pollen that’s lighter and more powdery and carries more easily – and because the wind is so random and inefficient, loads of pollen blows all around to make sure enough reaches the flowers, with plenty of it also going right up your nose.

So, yes, you’re sneezing now because oak trees are trying to have sex to make bouncing baby oak trees. That is, acorns, which you’ll see in the fall.