Lobelia inflata is an annual herb 15-100 cm tall, usually much branched, hairy, sap milky (Yatskievych 2006).
Leaves alternate, often overwintering as a rosette of dark green leaves; stalkless or almost so, blade 5-8 cm long, 1.5-3.5 cm wide, egg-shaped to widest above middle (obovate), hairy below, margin toothed.
Flowers pale blue to white, bilaterally symmetrical, 0.6-0.8 cm long, lower lip 3-lobed, hairy inside, sepals linear, 0.3-0.5 cm long, crowning an enlarged flower base surrounding the ovary, stamens fused in a tube 0.2-0.3 cm long; inflorescence of racemes at ends of branches, 10-20 cm long, lower bracts leaf-like, reduced upwards, flower stalks to 0.9 cm long, with 2 longer bracts at base; blooms and fruits July-Oct.
Fruit becoming dry, an inflated capsule 0.6-1 cm long, (Radford et al. 1968), consisting of the flower base (hypanthium) 0.7-1 cm long, 0.4-0.8 cm wide, opening at the top to release numerous, small seeds. Winter plant with inflated, papery fruit crowned by old sepals (Levine 1995).
Wetland status: FACU.
Frequency in NYC: Very infrequent.
Habitat: Open woods, fields or often a lawn and garden weed.
Notes: Plants poisonous due to up to 14 pyridine alkaloids similar to nicotine. Apparently smoked by American Indians and later used as a medicinal by Europeans. Misuse has caused fatalities (Kingsbury 1964).