In addition to being edible I found that the plant is a virtual pharmacy. This quote is from the site More Than Alive:
Excerpts from Practical Herbalism
Calendula is a remedy long used throughout Europe and the Americas for wound healing and ulcer treatments. Culpeper speaks of the flowers, either fresh or dried as being “much used in possets, broth, and drink as a comforter of the heart and spirits, and to expel any malignant or pestilential quality which might annoy them.” Ellingwood recommend it for varicose veins, chronic ulcers, capillary, engorgement, hepatic and splenic congestion, recent wounds and open sores, and severe burns. Calendula petals have often been used to add color and flavor to breads, soups, pickles, and salad oils.
Do not confuse this plant with the more common garden Marigold, French Marigold, or Tagetes.
Calendula is one of the best herbs for treating local skin problems. It may be used safely wherever there is an inflammation on the skin, whether due to infection or physical damage. It may be used for any external bleeding or wounds, bruising, or strains. It will also be of benefit in slow-healing wounds and skin ulcers. A very useful anti-septic ointment can be made by combining it with Comfrey root, Oregon Grape Root and Myrrh.