Seasonal spring allergies, or allergic sinusitis, are often caused by the pollen from grasses, trees, and weeds, and are usually the culprits behind that itchy face feeling that comes with each season. As trees, grasses, and weeds release their pollen from the male part of a flower or cone, wind, animals, and insects carry the powdery grains to fertilize other nearby plants of the same species.

We've created a guide of common spring pollen found in the Southern California region that may be the culprit(s) of your itchy or watery eyes, headaches, runny or itchy nose, achy sinus, sneezing, and coughing.

Here are the most common sources of pollen in Southern California.

Most types of grass release pollen only when they grow tall. A few types, including Bermuda, notoriously release pollen even when kept short. Perennial rye grass and tall fescue don’t usually flower and release pollen until they’re 12 inches or taller. Grass pollen usually is too small to be seen. Common grass pollen allergens include:

Tree pollen is very fine and powdery, and can be carried for miles on wind. Common tree pollen allergens include:

They aren’t just a source of frustration for gardeners. Many weeds such as Coyotebrush, Silverscale, and the varieties illustrated here can produce allergy-triggering pollen. Common weed pollen allergens include:

Click here for a printable Allergen Infographic.