Lobelia siphilitica is a clump forming perennial that thrives in a moist location. It adapts well to different light conditions like sun or shade as long as it has consistent moisture. The tubular blue flowers start to bloom in July and continue into September. Hummingbirds are enticed by these flowers.
[Photo: Lobelia_siphilitica_001; Credit: I, SB Johnny, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons]