Coriander seed is a memeber of the parsley family. The seeds are used as a seasoning. When sprouted the leaves are referred to as cilantro or Chinese parsley. Coriander is available ground or whole.
The whole coriander seed is frequently used in Hispanic, Asian and some European cooking.
Whole coriander seed can be purchased in most well-stocked grocery stores. You can typically find it in bulk at Whole Foods Markets. You can also look for it in Hispanic and Asian markets.