On Wed, 26 Jun 2013 02:01:03 +0000, Kay Lancaster wrote:

"Natura abhorret a vacuo"

Well, there's plenty of sunlight, poor soils, and no water to speak
of ... so, you're right - the only thing that grows are the weeds.

In fact, as you surmised, on my unwatered lawn, are basically these
two plants (wild mustard and some kind of other nasty looking thing):
http://www4.picturepush.com/photo/a/...g/13411202.jpg

Looking closer at the nasty looking thing, it has nasty leaves:
http://www2.picturepush.com/photo/a/...g/13411200.jpg

And, a nasty purplish headress:
http://www5.picturepush.com/photo/a/...g/13411198.jpg

I think it's some kind of horrid thistle all over my fescue lawn:
http://www3.picturepush.com/photo/a/...g/13411201.jpg