Easily grown in rich, humusy, medium to wet soils in full sun to part shade. Needs constant moisture. Will tolerate full sun in cool, northern climates, but otherwise appreciates part shade. Divide clumps in spring as needed. May self-seed in optimum growing conditions, forming attractive colonies.
Noteworthy CharacteristicsLobelia siphilitica, commonly called great lobelia or blue cardinal flower, is a Missouri native perennial which typically grows in moist to wet locations along streams, sloughs, springs, swamps, meadows and in low wooded areas. A clump-forming perennial which features light to dark blue, tubular, 2-lipped flowers with the three lobes of the lower lip appearing more prominent than the two lobes of the upper lip. Flowers arise from the upper leaf axils forming a dense terminal raceme atop stiff, unbranched, leafy stalks typically rising 2-3' tall. Finely-toothed, lance-shaped, light green leaves (to 5" long). Late summer bloom period.
Genus name honors Matthias de l'Obel (1538-1616), French physician and botanist, who with Pierre Pena wrote Stirpium Adversaria Nova (1570) which detailed a new plant classification system based upon leaves.
Species name of siphilitica arose from a prior medicinal use of the plant in the treatment of venereal disease.
Courtesy of the MIssouri Botanical Garden
Link to the Missouri Botanical Garden