Horseweed, or Conyza canadensis, is a common annual plant which is generally considered to be an invasive and unwanted weed. Native to North America, it is now found in many other parts of the world, including Europe and South America. It is relatively large, getting as high as seven feet (2.1 m) tall, and grows rapidly. Often found in open places such as fields, empty lots, and along roadsides, it can become problematic as it will also invade the fields of food crops and compete with them for resources.
In spite of its somewhat undesirable status, horseweed does have some valuable healing qualities. Originally used by Native Americans as a medicinal plant, it is still used as an herbal remedy for certain ailments. Its primary healing component is thought to be the tannins contained in the plant. The leaves, stem, or flowers may be utilized, or an essential oil extracted from the fresh plants, known as oil of erigeron, can also be employed for therapeutic purposes.
One important property of horseweed is its diuretic effect. This quality makes it very useful as a treatment for bladder and kidney issues, as well as for diseases that affect the urinary tract such as gonorrhea. The leaves and flowers of the plant can be steeped in hot water to make a tea, which can then be drunk for this purpose.
Digestive issues can also be treated using horseweed. Traditionally, Native Americans treated dysentary with it, and it has also been found to help ease diarrhea. The plant is considered to have tonic properties, making it useful for treating discomfort from indigestion, food allergies, and leaky gut syndrome. It has also proven effective for getting rid of intestinal parasites.
Another common use for horseweed is as an insect repellent and insecticide. One of the plant's alternative names, fleabane, is thought to be an indication of this property. It may be helpful in keeping insects from landing on the skin and biting or stinging, and for driving away infestations such as lice.
Due to its hemostatic and astringent qualities, horseweed may be employed to help stop bleeding in a variety of situations. It can be applied topically to small cuts and wounds. It is thought to be useful in treating minor hemorrhaging in many organs, such as the stomach, bladder, and uterus. A common area where this property has shown useful is in the treatment of bleeding hemorrhoids.