Coreopsis was my first thought.

Mine as well. When it blooms, you'll know for sure.

I was out this morning weeding and came across a leaf cluster nearly identical to the one in this photo - and like yours, there were several other ones nearby! I have coreopsis in this bed, so I would almost certainly identify it as such, except that my coreopsis plants right now are dying back, blooms spent and seeding. I suppose that both stages could be present, don't know enough to say for sure.