tankboy posted...
Corn, wheat, oats, and rice, are all grasses.
They are grasses we only eat the seeds of, not the leaves (for the most part). We could eat cooked leaves of most of those but they are essentially worthless in terms of nutrition.
Your standard lawn grass is not the same biologically as domesticated grain crops. Eating grass seeds would be possible but the actual leaves - the "grass" part of grass - contains enough silica minerals to wreck your teeth if you ate any significant amount of it. It would still be of minimal nutritional value but better than nothing, and historically people have eaten grass in extreme famines. If for some reason you find yourself in that situation, probably the best method would be to make a smoothie out of it to avoid chewing microscopic silica bits.
Part of the value of animal husbandry is to turn large quantities of unusable plant matter into usable food products. Grass is shit to eat but goats, cows, rabbits, etc. are much easier to eat.