The intensely red flowers of Cardinal flower (Lobelia cardinalis) catch the eye — even from a distance — in late summer. This next photo shows flower buds, an opening flower, and several fully open two-lipped Cardinal flower blossoms on the raceme.
As you might guess, the long flower tube can be penetrated by hummingbirds and butterflies for the nectar at the bottom. While reaching for the nectar, the pollinator brushes against the anthers of newly opening flowers and gathers pollen which is then supplied to an open stigma of another flower when the pollinator seeks more nectar elsewhere in the inflorescence.
With successful fertilization, the seeds develop within a seed capsule partially enclosed by the flower’s calyx. This image shows the dried flower hanging from the seed capsule. The calyx is beginning to turn from light green to brown.
Watch this video to learn how Cardinal flower (Lobelia cardinalis) moves through its annual life cycle as a perennial, to see how it grows a new basal rosette in the fall, and to view its tiny seeds.