The difference between seeds and spices is a haze one, as many spices are themselves seeds. The distinction seems to be made between those that impart their flavor to other foods (for example, caraway, celery and mustard), which are regarded as spices, and those that retain their own flavor (for example, poppy seeds). All seeds, especially pumpkin, sunflower and sesame, are rich in essential minerals and vitamins, and they are also exceedingly high in kilojoules.
Black seeds, such as poppy seeds, come in useful for adding a color contrast to pale dishes. Both black mustard seeds and black (unhulled) sesame seeds can be bought in India shops, as can small black seeds called kalongi, which have a pleasant, earthy flavor.
** Asian Recipes