At this time of year, this stuff is one of the things ruling, blanketing the roadsides in this area, where not mowed. Possibly in many areas, it's hard to notice going faster than about 25 MPH, even if blooming profusely. I've not noticed butterflies flocking to it over other plants.
There are at least a billion of these blooms in this pic I took yesterday. At any given moment there are many butterflies in my small yard, gulf fritillaries, and tiger and black swallowtails but I didn't notice any creeping for a mile down this road at about 5 MPH (and back,) stopping often to get out and take pics, besides occasional cabbage whites and little yellows. Around where I am, I see no evidence of the value of spreading this invasive plant any more. I'm sure it IS all about location, both for how the plants/seeds perform, and their use as a nectar source. Many plants are that way.
Photgraphed in macro though, the flowers sure are cute!! I love tiny flowers!
