Dragons can actually eat a wide variety of flowers but, I would be reluctant of feeding them if from out in your yard. Unless you live way out in the middle of no where and there are no pesticides used and or miracle grow.
This is from the diet section of the sites BD
Caresheet!
Edible Plants and Flowers
Babies Tears
Carnations (petals)
Chamomile (English)
Clover
Dahlia (flowerhead)
Dandelions (flowerhead, leaves)
Day Lillies (flowerhead)
Fennel
Ficus (leaves)
Geraniums (flowers, leaves)
Hibuscus (flowers, leaves)
Hollyhock (flowers, leaves)
Impatiens
Johnny-Jump (flowers)
Lavendaer
Maple (leaves)
Mint
Mulberry (leaves)
Nasturtium (flower, leaves)
Oregano
Pansies (flower)
Petunias
Roses (petals)
Rosemary (flowers, leaves)
Sage (flowers, leaves)
Thyme (flowers, leaves)
Yucca (flowers)
I do not see daisy's