This is Lobelia spicata, also known as Palespike Lobelia, and Spiked Lobelia. This is a popular plant with small butterflies and skippers, but the bees are the ones who really love to gather nectar here. These plants can get about 3 feet high and prefer to live in the sun or partial shade, blooming from the middle of Summer until early Fall. This plant requires moisture and cannot be allowed to dry out. USDA Hardiness Zones 4 to 9.