fresh coriander
The fresh leaves and tender stems of the coriander plant (called cilantro in North America), with a fresh, citrusy aroma.
Fresh coriander, sold as cilantro in North America, is found in most larger supermarkets in bunches or pots, and reliably and cheaply in Asian, Turkish and Middle Eastern grocers. Some people perceive it as soapy, a genetic trait that cooking does little to change.
Substitute:
There is no true substitute. Flat-leaf parsley gives the same green freshness, but the citrusy aroma will be missing.