2. Lobelia inflata L. (Indian tobacco, inflated lobelia)
Pl. 331 c, d;
Map 1409
Plants annual,
with taproots. Stems 20–90 cm tall, erect or ascending, unbranched or more
commonly moderately branched toward the tip, not winged, moderately to densely
pubescent with short, curved to more or less spreading hairs. Leaves sessile or
the lowermost leaves sometimes with a short, winged petiole, gradually reduced
above the stem base. Leaf blades 2–11 cm long, 1.0–3.5 cm wide, oblong-elliptic
to elliptic, ovate, or obovate, tapered at the base, the margins finely to
relatively coarsely and sometimes irregularly scalloped or bluntly toothed, the
upper surface glabrous or with sparse, more or less appressed hairs, the
undersurface moderately pubescent with curved hairs. Inflorescences loosely
flowered narrow racemes, the axis moderately to densely hairy, the bracts
similar to the adjacent leaves toward the base, the upper bracts much shorter
(each flower also with a pair of minute bracts immediately below the calyx).
Calyces 5–9 mm long, the tube 2–3 mm long at flowering, becoming noticeably
enlarged and inflated as the fruit matures, the slender lobes 3–6 mm long,
lacking auricles. Corollas 5–8 mm long, white, sometimes bluish-tinged or with
bluish purple lobes, the tube 3–5 mm long, without longitudinal slits, the
lobes 2–3 mm long, the lower lip with a beard of dense hairs on the inner
surface toward the base. Filament tube 2–3 mm long, the anther tube 1.2–1.8 mm
long. Fruits 6–10 mm long. Seeds 0.5–0.8 mm long, ellipsoid, the surface with a
series of minute pits and ridges, reddish brown. 2n=14. June–October.
Scattered nearly
throughout the state (eastern U.S. west to Minnesota, Nebraska, and Oklahoma;
Canada). Bottomland forests, openings of mesic to dry upland forests, banks of
streams and rivers, margins of ponds and lakes, and rarely marshes; also
pastures, fallow fields, gardens, railroads, roadsides, and moist, open,
disturbed areas.
Lobelia
inflata is an
aggressive, sometimes weedy species often found in disturbed areas.