Flowering Plants
All parts of the ever-present dandelion can be eaten.
Water Lily: The leaf and unopened flower buds can be cooked, while the tuberous rootstock can be prepared like potatoes.
Field Mustard: From the leaves to the buds to the seeds, the entire plant can be eaten, just avoid the bitter upper-stem leaves.
Clover: Both red and white clover can be eaten. Reds should be soaked and boiled 5 to 10 minutes; white should be eaten before the flowers appear.
Burdock: The young leaves and inner roots and pith (remove the green rind) can be eaten as a salad, though the roots should be boiled first.
Chicory: The roots make an excellent coffee, and the young leaves can be eaten as a salad (the white underground parts) or boiled (the green parts).
Woody Plants
Acorns should be cooked first to remove tannins.
Staghorn sumac: The red berry clusters can be soaked in cold water and, once strained, make a cold tea.
Pine trees: All variety of pine needles can be steeped to make a hot tea rich in vitamins. Young, male cones can be cooked and eaten in an emergency, and the inner bark (as well as the inner bark of spruces and firs) can be used as flour.
Locust: The Black Locust flower clusters may be dipped in batter and fried as fritters. Honey locust can be nibbled as a mint.
Wild fruits: Fruits such as grapes, strawberries, blueberries and raspberries, can be eaten fresh. Other fruits like elderberries require some cooking.
Wild nuts: Beech, chestnut and chinquapin are all edible nuts that need only to be roasted to get at the kernels inside the outer husks.
Yucca: The petals can be used in salads; the fruits (of the Spanish Bayonet) should be halved, seeded and then baked in foil.
Miscellaneous Plants
Like the dandelion, there isn't much on a cattail that cannot be eaten.
Fiddleheads: So-called because of their shape, off bracken and ostrich ferns they may be eaten as-is or boiled (recommended for the bracken). Do NOT confuse them with hemlock, which is poisonous.
Bulrush: Found in mud or shallow waters, the young shoots may be eaten as greens and the tips of the rootstocks may be prepared like potatoes. Its pollen and seeds can be made into flowers.
Kelp: This edible seaweed is excellent in a soup or salad and is commonly found along coastal waters.
Moss: Various kinds, such as Icelandic and Reindeer, can be dried and powdered for use as a flour.
Mushrooms: There are edible mushrooms in the U.S.; however, only eat mushrooms you are 100 percent sure of. When in doubt, leave it out of your diet.