Lobelia siphilitica

Lobelia siphilitica, the great blue lobelia or great lobelia, is a plant species within the Campanulaceae family. It is a herbaceous, perennial dicot native to eastern and central Canada and United States. Growing up to three feet tall, it lives in zones 4 to 9 in moist to wet soils. It produces a spike of zygomorphic flowers in the late summer.