May flowers

Out playing in the yard this weekend (in between the raindrops!), gave me no excuses not to photograph one of our newest plants to bloom this spring. Being in the south, we've had all the spring first-blooms come and gone. I still don't know the name of this plant, but it is tall and stalky and blooms through a good portion of the summer! It was given to us by a neighbor when we first moved in and it's a quick grower (aka spreader). As with all the annuals we've added over the past 3 1/2 years of living in this house, it's always such a joy to see the flowers come back up each year.

edited to add:
Here's a photo of the full plant, if this can help anyone identify it. (Click to enlarge).
Thanks!