Ajwain seeds are also known as carom seeds or bishop's weed and they're a spice that's been around for a long time. Ajwain seeds were pressed into ajwain oil, and were originally used in the Indian herbal medicine practice, Ayurveda. They were often used as a remedy for a lot of household illnesses, as well as for post-partum nursing mothers. Ajwain, or carom, was then co-opted into everyday cooking in order to enhance the nutritional and digestive benefits of dishes The dried fruit is ridged and a dark green/khaki colour, which looks very similar to cumin (which is why it's also referred to, sometimes, as Ethiopian cumin). Originally grown in West Asia, cultivation soon spread across the continent, mainly to India, and it's now cultivated in most of the sub-continent, as well as parts of the Middle-East (Iran) and East Africa.