Essential Spice Oregano Flakes are an herb composed of the dried leaves of the oregano plant. The plant has tiny leaves that lend a pungent aroma and strong flavor to a variety of savory foods. When in bloom, the plant sports pink or purple flowers, which are also edible. As an herb, it is gluten-free and suitable for vegan and paleo diets. The aroma of oregano has a camphor note. The taste is pungent and described as earthy and green with some mint and hay. It can be slightly bitter.