Celery was used as early as the 5th century by the Chinese, and widely used in Indian Ayurvedic practices. Celery has a complex,strong, sweet, and spicy aroma. The seeds are the primary repository for essential oil. Limonene, the dominant constituent in Celery Seed oil is also found in refreshing citrus peel and fir needle oils. The oil has a calming, relaxing, and positive aroma. Celery seed oil has a distinct, strong flavour.