Bamboo-like with purple flowers
This plant spreads all over and likes to gather as clumps. It's basically tall skinny dark sticks that have a purple flower in the spring. They have shallow roots and pull up very easily. I'm pretty sure it's not Mexican Petunia. It looks like a bamboo plant but I haven't seen bamboo like this before.
Here are images: http://img410.imageshack.us/gal.php?g=plants01.jpg