Edible flowers are more than pretty decoration, and can bring major flavour to a dish — I once had some that tasted like garlic — but I will admit I have a hard time identifying them. Luckily, this graphic from Lucky Peach can help with that.
Once you're familiar with what various edible flowers look like, click the link below to see what they would pair well with. I think borage, which has a vaguely cucumber-like flavour, would be great on a potato or chicken salad, and mint marigold would really sing in a summery cocktail.
Floral Food Faces [Lucky Peach]