Coreopsis verticillata

–  aka Tickseed, yellow flowers bloom atop slender, erect stems from spring to early summer
–  18 – 24″ tall and 12 – 24″ wide
–  Full sun to part shade
–  Blooms spring through summer
–  Well-drained soil
–  Forms dense, upright clumps from the base, creating a visual mass. Moderate spread through rhizomes and self-seeding.