Huanzontles (Chenopodium album L.) at the Los Colorines restaurant in Cuernavaca, Mexico.  Commonly known as Lamb's Quarters, this dish is prepared from the seed heads of the plant (for recipe). 

(More on Lamb's Quarters and close cousin Quinoa)

(Also, see Epazote)

More as an edible wild plant
Lamb's Quarters are a common garden hobo that I encourage and nurture.  A single large plant supplies enough food to feed twenty people.  The plant's name comes from the shape of its leaf.  Note in the photo below that the leaf is light green on top and whitish underneath.  Plants will range from small (3  or 4 seed heads) to large (over 50 seed heads). 

Food:  Fresh leaves lightly cooked provide vitamin C and A include seeds and get a healthful dose of essential amino acids.   Add the leaves to spinach, throw a few in a tossed salad (older leaves blanch first).  Great in bean soups.   Or serve in egg dishes with green chilis or salsa verde.
You may par boil and freeze seed heads as seen below.  seeds may be cut into soup or ground into flour for breakfast meal.   Montana Indian tribe ground seeds into flour and made flat bread. 

Medicine: In Mexico, the cooked leaves and seed heads are believed to keep the digestive system clean and healthy.  Cree used leaves in decoction for arthritis, rheumatism.  Joints and limbs were washed with the decoction.  Inuit people believe the leaves cooked with beans dispel gas.  Iroquois used cold infusion of plant to treat diarrhea.   High vitamin C content made the plant useful for preventing scurvy.
Seed heads opposite photo are par boiled, bundled and frozen.  They may be batter dipped and fried or rolled in beaten egg and saute.  Eating technique involves stripping heads of leaves and seeds by running stem through semi clenched teeth.

(Recipe)