This plant, the bunchberry, of the Dogwood family, grows abundantly on the private island here in Maine. After researching it, I tasted the berries and leaves. As Samuel Thayer says in his book, Natures' Garden, A guide to Identifying, Harvesting and Preparing Edible Wild Plants, the berries are very mild. I can see using them, as he suggests, to cook a sauce, make jelly, or even utilize in a wild fruit salad. The only caveat, there is a tiny seed in each berry.
However, this isn't a problem if you cook and strain, or sieve like applesauce, a whole pot of berries.
Unfortunately, I did not see where Thayer details if the leaves are edible or inedible. I tasted one and found it quite mild as well and so arrived at a tentative conclusion that the leaf would make a great garden salad in a survival situation.
Further testing under survival conditions would include adding a few leaves, at intervals and wait for any adverse effects.
In the interest of saving labor, and therefor calories, I try to harvest as much of the wild plant as possible, not just the leaves, or not just the berries, or not just the root.
