Texas Gardening: Wildflower I.D., 0 by bigbubbles

bigbubbles wrote:
These flowers have been blooming all summer at the lake in a neighbor's yard. The leaves are a little thick, not like a usual sunflower. They didn't plant them. When the area in front of their dock was dredged, the guys dumped some of the sludge into the flower bed. And the flowers popped up. They are also covered with caterpillars now. I took some seed to plant here, but want to know what I'm getting into in case they're invasive.