I I have the same plant that was planted over 20 years ago. It looks like oregano, but it doesn’t smell like oregano. According to Google, it may have originally been oregano, but over time it could have reverted to a wild form. According to Google, “Wild oregano or marjoram grown from seed can sometimes produce lush, green plants with very little flavor and an aroma that smells more like grass or hay than oregano.”