Lobelia siphilitica, the great blue lobelia, is a plant species within the Campanulaceae family. It is an 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.
It blooms from August to October. It is a short lived perennial (with each plant living for only a few years).
Although self-compatible, a flower is unable to offer pollen to itself and it must be pollinated by insects (primarily bees in the Bombus genus).
^ abcCaruso, C. M. (2006), "Plasticity of inflorescence traits in Lobelia siphilitica (Lobeliaceae) in response to soil water availability", American Journal of Botany93 (4): 531–8, doi:10.3732/ajb.93.4.531, PMID21646213