Lobelia siphilitica indiana dunes

Family:     Campanulaceae (bellflower family)

Duration:  Perennial

Height:     110 cm (up to 4 ft)

Blooming: July-Oct.


Great Blue Lobelia

Lobelia siphilitica  L.

Herbaceous unbranched, short-lived perennial


Stem is angular and a soft green color. It can be sparsely hairy of glabrous (not hairy).

Flowers are borne on spike-like terminal clusters that can be up to 61 cm (2 ft) long. Along that spike are numerous white-throated, blue, tubular flowers. The flowers form in late summer and are up to 3.8 cm (1.5 in) long. The two lipped flowers face upward and have two lobes on their upper lip and three lobes on their lower lip.

Leaves: young leaves are up to 13 cm (5 in) long, ellipse-shaped with shallow irregular teeth and pale margins form at the base of the plant. Yellowish-green sap is apparent when leaf is broken. Mature leaves are ellipse-shaped, longer than wide, and form alternately along the stem. Leaves are arranged alternately.

Sun: Full to part sun

Ideal Conditions:  Saturated open to shaded conditions, can tolerate moist soils.

INPAWS Native Communities:  Water's Edge (sun)



Bonap map - Lobelia

Illinois Wildflowers - Great Blue Lobelia

Michigan Flora - Lobelia siphilitica

Thompson, S.W. and T.G. Lammers. 1997. Phenetic analysis of morphological variation in the Lobelia cardinalis complex (Campanulaceae: Lobelioideae). Systematic Botany: 315-331.

Lobelia siphilitica indiana dunes

Comments: It is hypothesized by Thompson and Lammers (1997) that Lobelia siphilitica was the evolutionary parent species of Lobelia cardinalis.  The lobelia flowers are actually upside down or inverted.  The three bottom lobes are actually the upper lobes and vice versa.  

Etymology: The name Lobelia comes from a 16th century botanist Mathias de Lobel. The epithet name, siphilitica, came from the belief that the roots could cure syphilis.

all photos by Nathanael Pilla

Species Present and Native