Lobelia siphilitica

Species Native to Missouri
Common Name: blue cardinal flower 
Type: Herbaceous perennial
Family: Campanulaceae
Native Range: Eastern North America
Zone: 4 to 9
Height: 2.00 to 3.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: July to September
Bloom Description: Blue
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Low
Suggested Use: Naturalize, Rain Garden
Flower: Showy
Tolerate: Deer, Heavy Shade, Wet Soil

Culture

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 Characteristics

Lobelia 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.

Problems

No known serious insect or disease problems. Snails and slugs may damage the foliage.

Uses

Provides late summer bloom to the perennial border, wild garden, native plant garden, woodland garden or naturalized planting. Also effective near ponds or streams.