Kalm's Lobelia
Lobelia kalmii
Campanulaceae (Bellflower family)

Description: This perennial wildflower is -1' tall and either branched or unbranched. The slender stem(s) is light green to purple. Alternate leaves about -2" long and 1-5 mm. across occur along the stem(s). The leaves are light to medium green, linear to linear-oblong in shape, and usually smooth along their margins. The central stem and any lateral stems terminate in racemes of flowers; the flowers are distributed sparsely along the rachis of each raceme. Each flower is -" across, consisting of a 2-lipped tubular corolla that is light blue (rarely white), a bell-shaped (campanulate) calyx with 5 slender teeth that are light green to purple, 5 stamens, and a 2-celled ovary with a single style. The stamens tightly surround the style. The upper lip of the corolla is divided into 2 small narrow lobes, while the lower lip is divided into 3 large lobes. At the base of the corolla's lower lip, there is a conspicuous patch of white; sometimes this patch becomes yellow along its upper boundary near the throat of the corolla. The corolla is hairless throughout, while sometimes the bottom of the calyx is pubescent. The slender pedicels of the flowers are -1" long; they are light green to purple and either glabrous or minutely pubescent. Toward the middle of each pedicel there is a tiny linear bractlet; at the base of each pedicel there is a linear bract that is about the same length as the pedicel. The blooming period occurs from mid-summer to early fall and lasts about 1 month. Afterwards, the flowers are replaced by seed capsules about 4 mm. across; each capsule splits open at its apex to release numerous tiny seeds that are narrowly oblongoid and compressed (somewhat flattened) in shape. The seeds are small enough to be blown about by the wind or transported by water. The root system is shallow and fibrous.

Cultivation: The preference is full sun, wet to consistently moist conditions, and soil that is sandy to sandy-peaty and calcareous. Episodic periods of shallow water are tolerated.

Range & Habitat: The native Kalm's Lobelia occurs in northern Illinois, where it is uncommon (see Distribution Map). Illinois lies along the southern range limit of this species. Habitats include grassy fens, wet sandy meadows, borders of interdunal swales, low areas along springs, and bogs. This conservative species is found in high quality wetlands where the original flora remains intact.

Faunal Associations:
Very little is known about floral-faunal relationships for this species. The flowers are probably cross-pollinated by various bees and small butterflies. Like other Lobelia spp., Kalm's Lobelia has an acrid sap that is more or less toxic to mammalian herbivores.

Photographic Location: A fen in NE Illinois. The photographs were taken by Lisa Culp, Copyright 2011.

Comments: This is one of the less common Lobelia species in Illinois. Kalm's Lobelia has a delicate beauty that derives from its pastel blue flowers and slender foliage. It is somewhat similar in appearance to Pale-Spiked Lobelia (Lobelia spicata), but its leaves are more narrow (less than " across). Other Lobelia species in the state also have wider leaves, and some species have larger flowers. Another common name of Lobelia kalmii is Brook Lobelia.