Today's featured weed is ragweed, Ambrosia artemisiifolia.
Ragweed is also known as common ragweed, hayfever weed, bitterweed, bloodweed, crownweed, mayweed and bane of allergy sufferers everywhere.
It's in full bloom around here right now, and my head can tell. The seeds of this amazing plant can lie dormant in the soil for 40 years, just waiting to be unearthed and spread truckloads of tiny pollen grains EVERYWHERE. Plus – bonus – changing weather patterns have extended the ragweed season through much of the United States. (BTW, just for the record, the climate has been changing as long as the planet's been around. The weather has raised and toppled empires – but that's another post.)
Range and Identification of Common Ragweed
Common ragweed is actually native to North America, where it is found throughout the United States and most of Canada (see USDA map). (Aren't we lucky?) Some studies indicate it produces up to 90% of the allergy causing pollen in the United States. It has also spread over much of Europe, where it has become a problematic invasive species.
The leaves are fern-like – it looks pretty innocent when it's small.
It's an annual, so it's killed off every year, but like I said earlier, those seeds stick around for a long time. The stems are fuzzy, and the green flowers appear on spikes with their own set of leaves above an existing leaf. The stems are filled, not hollow. It prefers full sun, disturbed and slightly acidic soil, and can tolerate drought. (It's a good weed.) In a study of several different populations
in France the annual seed production per plant ranged from 346 to 6,114 with about 2,500 seeds per year as a mean. (See link.) DON'T LET THESE THINGS GO TO SEED!
Ragweed as Food and Habitat for Wildlife
Believe it or not, ragweed is useful. It produce seeds that are rich in oil and provide winter food for birds and small mammals. Fairfax County Public schools website states that “Ragweed is a good source of food and cover for wildlife. Eastern Cottontails eat the plants, and insects, such as grasshoppers, eat the leaves. Some animals which eat ragweed seeds include: Meadow Vole, Dark-eyed Junco, Brown-headed Cowbird, Northern Bobwhite, Purple Finch, Mourning Dove, American Goldfinch, and Red-bellied Woodpecker.”
Medicinal Uses of Common Ragweed
Judith C. Evans states in her article “History and Medicinal Uses of Ragweed“:
Ragweed’s medicinal properties include: astringent, antiseptic, emetic, emollient, and febrifuge. Early American physicians recognized ragweed’s medicinal uses, and Native Americans valued it as a topical and internal remedy. Healers and herbalists prepare remedies from the roots and leaves. Crush the leaves and apply the juice to soothe insect bites and poison ivy rashes. Native Americans prepared a poultice from crushed leaves to relieve swelling and prevent infection.
Ragweed also provides aid for internal ailments. Herbalists value ragweed root tea as a remedy for nausea, fevers, and menstrual disorders; Native Americans used the root tea as a laxative. For years, Ozark herbalists have treated diarrhea with tea prepared from the leaves. Ragweed pollen is used in homeopathic remedies for treatment of hay fever symptoms.
Personally, I have not tried it, and would suggest you be careful with taking it internally, especially if you have any type of allergic reaction to the pollen. Next time I get a mosquito bite, I may try the sap to see if it does indeed sooth the itch.
If you are one of the folks who is bothered by ragweed pollen, unfortunately there is no cure. The Asthma and Allergy Foundation of America recommends antihistamines and immunotherapy. I've noticed that when I watch my diet (plenty of fat to keep nasal and lung membranes well lubricated, plenty of live culture foods, less sugar), my allergy symptoms are much milder.
Update: I've also found out that direct contact with the ragweed plant can cause mild contact dermatitis, after pulling quite a number of ragweed plants bare handed from the side of the driveway. DernNet NZ confirms I'm not the only one this has happened to. About a day and a half after the pulling, I woke up with a palm full of small, itchy bumps. I put some plantain oil on it.
If you've enjoyed the post, please share it. This is one weed I'm not a fan of, but it does serve a purpose. If you've tried any of the medicinal uses, please let me know.