Fennel is native to Southern Europe and grown extensively all over Europe, Middle-East, China, India, and Turkey. This herbaceous plant reaches up to 2 meters (about 6 feet) in height with deep green feathery (lacy) leaves and bears golden-yellow flowers in umbels. In general, fennel seeds are harvested when their seed heads turn light-brown. The seeds, which closely resemble that of anise seeds in appearance, feature oblong or curved (comma) shape, about 3-4 mm long, light brown-color with fine vertical stripes over their surface.
Fennel seeds are available year around in the markets either in the form of seeds or in processed powder form. In the store, buy whole fennel seeds instead of powder since, oftentimes it may contain adulterated spicy powders.