Grass pollen is dominant in the summer. Grasses are a large and diverse plant with 8000 species in 500 genera found all over the world. 1200 species are native to North America. Bamboo, wheat, and corn belong to the grass family.
Grasses do have flowers, but they are small and lack showy petals.
Most grasses depend on wind to pollinate . Many species shed their pollen in early morning. Some grass species, like wheat, have become self-pollinated. Grass allergenicity Orchard grass season is from May to June. The Blue or June grasses season is from May to July.