Plant of the Week
Range map of cardinal flower. States are colored green where the species may be found. USDA, NRCS. 2021. The PLANTS Database (https://plants.usda.gov, 16 August 2021). National Plant Data Team, Greensboro, NC USA.
Cardinal Flower (Lobelia cardinalis L.)
By Larry Stritch
Cardinal flower is a brilliant scarlet-colored native wildflower that grows in marshes, stream banks and low woods. Its extremely showy blossoms can be recognized at considerable distance. Few native plants have flowers of such intense color as this common herbaceous perennial. The Cardinal flower is a member of the Bluebell Family. It was named after the Flemish botanist, Matthias de L'Obel (1538-1616).
The blossoms are delicate, gradually opening from bottom to top on two to four foot spikes. Five petals are united into a two-lipped corolla. The lower lip has three very prominent lobes; the upper lip has two small ones. Five stamens are joined forming a red tube around the style and are topped by bearded anthers which form a mustache-looking brush. Cardinal Flower blooms in late summer (July to September).
Lobelia cardinalis, cardinal flower. Photo by Alan S. Heilman, University of Tennessee Herbarium.
Lobelia cardinalis habitat. Photo by Penny Stritch, Harken Hollow Photography.
Beneath the flower spikes are numerous dark green leaves, tapered at both ends. Flowers are very attractive to butterflies and hummingbirds. The many seeds come in two-celled pods which open at the top. Cardinal flowers can be grown in full sun or very light shade but probably grow best in filtered light. The roots require moisture so mulch is needed, or it can be planted on the edge of a marsh or pond.