Lobelia siphilitica, the great blue 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.
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