Bellflower family (Campanulaceae)
Description: This plant is a summer annual about ½–2½' tall and more or less erect. It is unbranched, or branches occasionally in the upper half. The angular stems have bristly white hairs; these hairs are less abundant on the upper stems. The alternate leaves are up to 2½" long and 1" across, becoming smaller as they ascend the stems. They are lanceolate to ovate in shape and crenate or bluntly dentate along the margins. The upper surface of each leaf is largely hairless, while the lower surface has a few hairs along the major veins. The lower leaves have short petioles, while the upper leaves are sessile. The central stem terminates in a spike-like raceme of flowers that extends to about one-half the length of the plant. Some of the upper side stems may terminate in shorter racemes. Each raceme has alternate leafy bracts that are similar in appearance to the leaves below, except that they are smaller. A single flower develops from the base of each bract on a short petiole; usually a few flowers are in bloom at the same time. Each flower is up to 1/3" (8 mm.) long; it consists of a tubular corolla with 5 spreading lobes and a short tubular calyx with 5 teeth that are long and spreading. The corolla is light blue-violet, light purple, or white. It has a cleft upper lip consisting of 2 small lobes and a cleft lower lip consisting of 3 lobes that are somewhat larger. The interior of the corolla is primarily white; its lower interior has 2 small yellow patches and tufts of fine white hair. The blooming period occurs from mid-summer through the fall and lasts about 2-3 months. There is no noticeable floral scent. After the corolla withers away, a globoid seed capsule develops that is about 1/3" (8 mm.) across. This capsule is completely enclosed by the persistent green calyx. There are several conspicuous ribs along the sides of this calyx. The seed capsule is divided into 2 cells and contains numerous tiny seeds; these seeds are small enough to be blown about by the wind. The root system consists of a taproot.
Cultivation: The preference is partial sun, moist to dry conditions, and a soil that contains loam, clay loam, or rocky material. Poor soil is readily tolerated, although this will stunt the growth of the plants somewhat.
Range & Habitat: The native Indian Tobacco is a fairly common plant that occurs in most areas of Illinois; it is less common or absent in a few areas of northern Illinois (see Distribution Map). Habitats include open deciduous woodlands, savannas, thickets, areas along woodland paths, powerline clearances in wooded areas, partially shaded seeps, and abandoned fields. This species prefers areas with a history of disturbance, particularly when this removes some of the overhead canopy in wooded areas. It is somewhat weedy.
Faunal Associations: The nectar of the flowers attracts small bees, mainly Halictid bees. The acrid foliage is highly toxic and avoided by mammalian herbivores, including White-Tailed Deer. The tiny seeds appear to be of little interest to birds.
Photographic Location: A powerline clearance in Busey Woods at Urbana, Illinois.
Comments: Notwithstanding the common name, the foliage of Indian Tobacco should be neither chewed nor smoked as it is highly acrid and toxic. While Indian Tobacco is an annual, other Lobelia spp. (Lobelias) in Illinois are perennials with larger flowers. Indian Tobacco resembles Lobelia spicata (Pale-Spiked Lobelia), but the latter has slightly larger flowers (up to ½" long) and its stems have shorter hairs or they are glabrous. Another species, Lobelia kalmii (Kalm's Lobelia), occurs in various wetlands and is uncommon in Illinois. It has larger flowers, more narrow leaves, and lacks spreading hairs on its stems. Indian Tobacco is distinctive because its calyxes become conspicuously inflated from the developing seed capsules; this makes it relatively easy to identify. The calyxes of other Lobelias don't inflate after the corollas of their flowers have withered away.