Green Cardamom (Elaichi) is a small green triangular (in cross section) seed pod, with a thin and papery outer shell, with the inside containing small, aromatic, dark brown to black seeds. It is the third most expensive spices by weight, out-priced in market value only by saffron and vanilla. It has a strong, unique, intensely aromatic, resinous and quite surprisingly refreshing fragrance. In India, it is often used as a mouth-freshener or after-mint. In cooking, it is used both in savory dishes as well as desserts and imparts characteristic flavors to both. Interestingly, while it is used primarily in Asian, Middle-Eastern and a few Nordic countries, the current world's largest producer of Cardamom is Guatemala - which produces 25,000 to 29,000 metric tons. India and Sri Lanka produce about half that quantity (together) and perhaps use most of it ;)
In the US, although few Americans have probably tasted cardamom by itself - I would estimate that a large percentage of Americans have tasted it in the form of Starbucks Spiced Chai where Cardamom is a major ingredient (along with cinnamon, ginger root and cloves). While the ground spice is sold in the US and in other countries, this spice is best stored in pod form which helps preserve the essential aromatic oils. Although the pods may lose their distinctive green color over time, the seeds will retain most of the flavor.