RAGWEED (AMBROSIA SPECIES)
"Ragweed is the number one cause of hay fever, not only because of its specific irritating qualities, but also because of its abundance. It is found in all of North America, where it rapidly spreads through disturbed soil along driveways, roads, railbeds, sidewalks, and cultivated fields. Worse, it flowers all summer long.
It has been declared a noxious weed in most jurisdictions, and authorities release a pollen index throughout the growing season that includes ragweed.
Ironically, ragweed belongs to the genus Ambrosia, which is Latin for “food of the gods.” Perhaps, the name derives from an obsolete medicinal application.
POISON LOCATION
Pollen of some species, especially ragweed. A microscopic view of the pollen grain itself shows the tiny hooks with which the pollen attaches to a target flower—or to the delicate mucous membranes of the eyes, nose, throat, and lungs of a hay fever sufferer!
POISON TYPE
Mechanical irritant, but no chemical toxin. The tendency to suffer from hay fever is inherited; sensitivity to different pollens arises after exposure to them, when the lymphoid tissues of the body are stimulated to produce special antibodies to the pollen. The antibodies stimulate localized production of compounds called histamines, which cause sneezing.
TYPICAL POISONING SCENARIO
Breathing-in an otherwise invigorating lungful of fresh air. Sadly, despite the widespread success of antihistamines and allergy shots, the only 100% reliable solution to hay fever is avoidance. Air filtration and air conditioning remove outdoor airborne allergens, but who would miss the whole summer, brief as it often is?
Incidentally, if you sneeze and sniffle through May–June, your problem is more likely to be trees like alder and birch; if June and July set your nose running, you’re more likely to be suffering from grass pollens. Only ragweed can keep you miserable all spring and summer.
SYMPTOMS
Ragweed pollen stimulates antibody production, which stimulates histamine production. Histamines, in turn, cause localized dilation of blood vessels (redness), increased fluid secretion (runny nose), tissue swelling (stuffed-up nostrils, puffy eyes), sneezing, and rhinitis (inflamed, itchy nose and throat). Severity varies with the individual, but repeated, severe attacks may result in asthma and/or secondary infections of inflamed tissue that cause chronic sinusitis, headaches, and insomnia.
RAGWEED POISON INFORMATION
Hay Fever allergens
Some people develop sensitivities to the physical properties of some plants, especially seeds or pollen.
Pollen is produced by all flowering plants; it is essential to the fertilization of flowers. Some plants depend upon the wind to pollinate the flowers. Buoyant pollen grains, especially from trees and grasses, blow from plant to plant.
Not all wind-pollinated plants are toxic, but they tend to produce copious amounts of dust-like pollen. In susceptible people, this irritating pollen causes hay fever. Many plants cause hay fever—grasses, alders, poplars, birches, elms, and maples, to name a few. Not everyone reacts to all allergenic plants.
Hay fever results in influenza- or cold-like symptoms, with a definite seasonality to the condition. Spring sufferers of hay fever are probably allergic to tree pollen; early summer brings on reactions to grasses; and fall sufferers probably can’t tolerate ragweed.
SEE ALSO
POISON PLANT LOOKUP
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