Coreopsis lanceolata (lance-leaf coreopsis)

Also known as sand coreopsis or tickseed due to the small black seeds. Showy yellow flowers attract many native bees, including a long-tongued bee that specializes on coreopsis. Blooms for several weeks, and can be extended further with deadheading. Tends to be a shorter-lived perennial, but it self-sows easily so typically persists in the garden. Listed as a species of special concern in Wisconsin.