When in need of some wild edibles, cattail roots are fairly good, especially in spring when their new shoots are young and succulent. Peel back the outer layers of rough, old growth and eat the younger growth. They can be eaten raw or boiled.
Also, old man's bear or witch's hair has the dual purpose of being edible (tastes like lettuce) and is a good fire starter when dry. Make sure you eat the dark green variety.
Native Americans used to bake bunches of it underground for a treat that tastes like black licorice.