Cuckoo Flower is rich in Vitamin C and minerals, including potassium, iron and magnesium, and can be eaten as a salad plant or taken as a tea. The fresh, aerial parts are used, i.e the young leaves, shoots and flowers. Because of its high levels of Vitamin C, it is a useful antiscorbutic, which means having the effect of preventing or curing scurvy.
Here is a lovely description from Nicholas Culpeper's Complete Herbal from 1653:
"Ladies-Smock, or Cuckow-Flower:
Place : They grow in moist places, and near to brooksides.
Time : They flower in April and May, and the lower leaves continue green all the Winter.
Government and virtues : They are under the dominion of the Moon, and very little inferior to Water Cresses in all their operations; they are excellently good for the scurvy, they provoke urine, and break the stone, and excellently warm a cold and weak stomach, restoring lost appetite, and help digestion."
Discovering such unexpected flora is yet another aspect to the joy of gardening wild. I'm trying to be very mindful while creating this garden - I want it to be a place rich in wildlife, as well as a place to grow our food. This beautiful wildflower is a wonderful example of what is already here, and what could too easily be dug up or 'weeded' out.
As there are only about half a dozen of them at the moment, I'm leaving their little area totally wild, and as they are perennials, I'm hopeful even more will come back next year.