Only wind-blown pollen causes allergies.
Allergies make millions of people miserable every year. The types of weeds that cause hay fever are weeds that depend on wind pollination, because their pollen is small and light enough to be inhaled by the sufferer. The pollen of plants such as goldenrod are too large and heavy to be inhaled, and rely on insects for pollination. The symptoms of hay fever are inflammation of the mucus membranes, runny and itchy nose, an itch in the roof of the mouth and sneezing.
Ragweed and Plantain
Common ragweed is often called hay fever weed due to its reputation as an allergen. It's a grayish green annual that grows in fields, roadsides, waste places in the Northeast, Midwest and other parts of the country. Its seeds are eaten by birds, and are available even in winter. Giant ragweed grows to 10 feet tall, especially in the East. It often takes over a field after a crop has been harvested. Plantains are found on lawns and other places. Most plantains have a base of long leaves from which flower spikes arise. The most common species of plantain in the United States are the buckthorn plantain and the broadleaf plantain, both of which originally came from Europe.
Nettle
The stinging nettle not only causes allergies, but has stinging hairs on its stems and leaves that raise a rash if you brush against them. Stinging nettle grows in neglected places, bottom land and along roadsides. Stinging nettles grow from 2 to 12 feet tall depending on the species and growing conditions. Most are perennials.
Goosefoot
Goosefoot is seen everywhere in the United States during the summer along roadsides, in fields, gardens, lawns, pastures and waste places. Goosefoot ranges in height from 1 to 6 feet. Some species have leaves that somewhat resemble goose feet, giving the plant its name. Some species are strongly scented, some are prickly and some are clammy. The flowers are tiny and produce abundant pollen, followed by small black or brown seeds that are just as abundant. The plant was brought over from Europe as a pot herb and is still used for greens.
Sorrel
Sheep sorrel originated in Eurasia and is now abundant throughout the United States in gardens, lawns, fields and waste places, preferring acid soil. When young, the sorrel is only a few inches high but later the flower stalk, full of tiny flowers, grows to a foot or more. The seeds are triangular and brownish, and the troublesome pollen is born on the wind. The leaves of sorrel are edible.
Timothy Grass
Many allergies are caused by grasses, including timothy grass, which grows in fields and roadsides and clearings, and has a bristly spike and tiny flowers. It makes for excellent hay and birds eat the seeds, but its pollen is a major allergen.
Tags: United States, waste places, along roadsides, causes allergies, feet tall, fields roadsides