Cardamom is the dried fruit of Elettaria cardamomum, a tall tropical relative of ginger whose papery, spindle-shaped green pods each hold a cluster of small, sticky black-brown seeds. Crushed, those seeds release an extraordinary aroma — cool and camphoraceous like eucalyptus, then bright and citrussy, then sweet, spicy and floral all at once. Costly enough to be called the "queen of spices," it perfumes Indian chai and garam masala, Arabic coffee, and the cardamom buns of Scandinavia.