It looks like some kind of Lobelia. A close up of the flower itself would be very helpful.
I believe it is a Cardinal Flower:
> This 1-6 ft. perennial has showy, red flowers in 8 in., terminal spikes. Each flower has three spreading lower petals and two upper petals, all united into a tube at the base. Erect leafy stems, often in clusters, with racemes of flowers resembling flaming red spires. The lower portion of the erect stem is lined with lance-shaped leaves.