The petals of most flowers that will later be edible fruits or berries can be eaten, but not all taste good. Elder flowers and basswood flowers are especially good. The idea of salad seems to have been brought back to France from America in the 18th century or so. Cucumbers are parboiled, then fussed with in many ways. So, although I've never seen this discussed in European cookbooks or food discussions, I think the very idea of salads came from Native people.
All vegetables lose some of their nutrient value in any kind of cooking.
Young people should be aware that delicious and healthful salads are part of our Native food traditions, so eat plenty of it.