Stephanie, That is Artemesia 'Oriental Limelight', and is very invasive in my zone so for me in fact it is a 'weed' in practice. I spent quite a bit of time digging it out several years ago.It looks nice in container combos but tends to crowd the other residents of the pot out after a time. Kathy in Napa

Great..Now that we know what they are, how do you rid of these horrible things..I saw this problem comming when my neighbors decided to let their yard be over run.. They gave up and let them win, until I stepped up to the plate to keep their yard up, and these things keep coming back.... They inched closer and closer to my manicured flower beds, and now I have them.. What works so I can get a head start next year? How do you kill weeds that have root feeders? Maybe Roundup? I hate chemicals..But if this the only way, I will use the stuff, even if it shortens my life..Arg Thanks so much...

Looks a lot like Silybum marianum / Staint Mary's Thistle. Here is a link that might be useful: Silybum marianum / Staint Mary's Thistle

Nutsedge--It needs to be poisoned, rather than pulled. As DC implies, it could be you are watering too much. Have you been getting buckets of rain this month like we have in Texas?