Cardamom

From the pages of Wikipedia:
The name cardamom is used for herbs within two genera of the ginger family Zingiberaceae, namely Elettaria and Amomum. Both varieties take the form of a small seedpod, triangular in cross-section and spindle-shaped, with a thin papery outer shell and small black seeds. Elettaria pods are light green in color, while Amomum pods are larger and dark brown.

Cardamom has a strong, unique taste, with an intensely aromatic fragrance. It is a common ingredient in Indian cooking, and is often used in baking in Nordic countries. One of the most expensive spices by weight, little is needed to impart the flavour. Cardamom is best stored in pod form, because once the seeds are exposed or ground, they quickly lose their flavour. However, high-quality ground cardamom is often more readily (and cheaply) available, and is an acceptable substitute. For recipes requiring whole cardamom pods, a generally accepted equivalent is 10 pods equals 1½ teaspoons of ground cardamom.