Despite the original posters overly extensive post, with certain questionable content, the central point is still quite vaild. We as a nation spend more money on grass than on any other crop. That by itself should be reason enough. Read up on the history of lawns and you'll find that they were orginally created as a means of demonstrating wealth (aka, I have this big area and I can afford to do nothing with it except grow grass I can't eat) Regarding the comments of junegem13 and zachslc, you might want to read up on the legal history of this movement. As it turns out, most weed laws (ones based on hight, not on noxious weeds) are unconstitutional. Nonetheless, if you are in a city or subdivision and decide to do a wildflower meadow where there is not an reasonable ordinance, then you should notify your neighbors and the city about why you are doing and the legal preceedants. The EPA has all this information. Regarding property values, that was the original complaint neighbors made against one landowner when she converted her lawn into meadow. When they were unable to demonstrate an actual decrease in property values, the city ordinance was ruled unconstitutional. Afterwards, the neighbors decided if they couldn't beat her that they'd join her and replace their own yards with meadows. Property values in that one neighborhood are now some of the highest in the city (Specific names and places, are available if you want them). Time and time again, lawn alternatives done correctly have shown to raise values, not lower them. In Charlottesville, VA local government is working on an ammendment to exclude native meadows from our weed ordinance. Other cities are doing the same very quicky, especially since the weed ordinance as written by many localites constitutes a legal liability to local governments.

Have a look at Elymus virginicus (Virginia Wild Rye) or Elymus canadensis (Canada Wild Rye). You want a cool-season bunch grass which can withstand the spring flood. It will re-grow in fall after the summer mowing.

Well, the obvious answer is clover of course. There are many varieties of clover. There are also quite a few varieties of ornamental grass. I recently asked a similar question, and wold told lyre leaf sage could survive mowing, and blue eyed grass could survive occasional mowing. I'm told ditch llilys can survive mowing. Of course, most bulbs can survive occasional mowing....particularly grape hyacinth. None of these would choke out weeds. Would creeping thyme work?

The Weedelia looks like what we call Singapore Daisy. It's a declared environmental weed, you can grow it but not distribute or dump it. I have it at my place. It's rampant during the wet season but gets burned back by the dry season. Rooted nodes along the stems seem to survive and that's where the new growth comes from during the wet season.