Grass IS edible, but in no way palatable. I doubt that you could choke down enough to do you any good, the seed is probably the least offensive, most "eatable" part of the plant, kind of bland and tasteless. Dandelions are great fixxed with bacon, drippings, and a little red wine vinegar, but if you're in a survival situation, just settle for the raw leaves eaten like a salad, and don't worry, dandelions don't have any poisonous look-alikes. Don't taste test unless it's a LAST resort, some wild edibles have deadly look-alikes.
There are quite a few (about a dozen around here) wild edibles that almost anybody can spot in their yard or at a park that are not only edible, but good, and good for you. With a little study, and the interest to take the time to get familiar with them, you can feed yourself fairly well.

Troy