Redtop seedhead

Plants that are allergenic or that cause dermatitis or mechanical injury are annoying, but the victim usually recovers. Wind-blown pollen generated by trees, grass, plants, and weeds can cause airbone allergies to some people. For the 40-50 million allergy sufferers in America, inhaling airborne allergens can produce a variety of allergic symptoms and because pollen grains are small and buoyant, they can remain airborne for hundreds of miles.

The following is a partial list of weeds that may cause allergic reactions: