Bishops Seeds (Ajvain) Standard  weed is a flowering plant. The seeds are used to make medicine. Bishop's weed is used for asthma, chest pain (angina), kidney stones, a skin disorder that causes white patches to develop on the skin (vitiligo), and scaly, itchy skin (psoriasis), but there is no good scientific evidence to support these uses. Be careful not to confuse bishop's weed (Ammi majus) with its more commonly used relative, khella (Ammi visnaga).