I found this information on a cooking site, I hope it helps you. "Bean blossoms have a sweet, beany flavor. Nasturtiums have a wonderfully peppery flavor similar to watercress and their pickled buds can be substituted for more expensive capers. Borage tastes like cucumber, and miniature pansies (Johny-Jump-Ups) have a mild wintergreen taste.
Violets, roses and lavender lend a sweet flavor to salads or desserts. Bright yellow calendulas are an economic alternative to expensive saffron, though not quite as pungent. Other flowers may have a spicy or peppermint flavor.
When in doubt, taste, but first be sure it's not poisonous. "
Find large list of edible and poisonous flowers on the following site: