Herbs with milky acrid juice, alternate leaves, and loosely racemed flowers. Corolla irregular, 5-lobed, the tube split down one side. Stamens 5, syngenesious, and commonly also monadelphous, free from the corolla. Calyx tube adherent to the many-seeded ovary. Style 1. The only genus is
1. L. Cardina'lis, L. (Cardinal Flower.) Corolla large, deep red. Stem simple, 2-3 feet high, smooth. Leaves oblong-lanceolate, slightly toothed. Bracts of the flowers leaf-like. - Low grounds.
2. L. syphilit'ica, L. (Great Lobelia.) Corolla rather large, light blue. Stem hairy, simple, 1-2 feet high. Leaves thin, acute at both ends, serrate. Calyx-lobes half as long as the corolla, the tube hemispherical. Flowers in a dense spike or raceme. - Low grounds.
3. L. inflata, L. (Indian Tobacco.) Flowers small, 1/6 of an inch long, pale blue. Stem leafy, branching, 8-18 inches high, pubescent. Leaves ovate or oblong, toothed.
Pods inflated. Racemes leafy. - Dry fields.
4. L. Spicata, Lam. Flowers small, 1/3 of an inch long, pale blue. Stem slender, erect, simple, 1-3 feet high, minutely pubescent below. Leaves barely toothed, the lower spathulate or obovate, the upper reduced to linear bracts. - Racemes long and naked. - Sandy soil.
5. L. Kal'mii, L. Flowers small, 1/3 of an inch long, light blue. Stem low, 4-18 inches high, very slender. Pedicels filiform, as long as the flowers, with 2 minute bractlets above the middle. Leaves mostly linear, the radical ones spathulate and the upper ones reduced to bristly bracts. - Wet rocks and banks, chiefly northward.
6. L. Dortman'na, L., (Water Lobelia) with small leaves, all tufted at the root, and a scape 5 or 6 inches long with a few small light-blue pedicelled flowers at the summit, occurs in the shallow borders of ponds in Muskoka.