Osha is a plant. Historically, the root has been used as medicine by Native American and Hispanic cultures.
Today, osha is used for sore throat, bronchitis, cough, common cold, influenza, swine flu, and pneumonia. It is also used to treat other viral infections including herpes and AIDS/HIV. Some people use it for indigestion.
Some people apply osha directly to the skin to keep wounds from getting infected.
Be careful not to confuse osha with the very poisonous plant hemlock. The leaves of the two plants are very similar. Osha must be identified by the root, which people say has an unpleasant celery-like odor. Be sure to buy osha from a reputable source, so you can feel confident that the product really is osha.
Osha grows at higher elevations in the western US and is difficult to cultivate. The popularity of osha has led to over-harvesting of the wild plant. As a result, osha has been designated an endangered plant by conservationists.
Warning: Not to be used during pregnancy.