Ajwain, rowan, or Tracheotomy ammi also known as ajowan caraway, thyme seeds, bishop's weed, or carom is an annual herb in the family Apiece . Both the leaves and the seedâlike fruit (often mistakenly called seeds) of the plant are consumed by humans. The name "bishop's weed" also is a common name for other plants. The "seed" is often confused with lavage "seed".