The Indian tobacco is frequently called wild tobacco, asthma-weed, gag-root.
The Indian tobacco is a hairy annual, with an erect branched stem from one to three feet high. The lower leaves are oval, from one to two and a half inches long with toothed margins and short stalks. The upper leaves have no stalks, and gradually diminish into leaf-like bracts. Its numerous pale blue flowers are small, two-lipped, and rather inconspicuous in the axils of the upper leaves. The seed-pods are inflated, nearly round, with ten prominent ribs, and contain numerous brown seeds, oblong and reticulated. The plant is in bloom from July to October.
It is commonly found in fields and thickets from Labrador to Saskatchewan. It is native to Canada.
The whole plant contains an acrid milky juice, and has an unpleasant burning taste. It is used medicinally. The leaves contain the poisonous narcotic alkaloid lobeline. Lobeline, as well as other constituents found in lobelia, is open to further investigation, but its action is well known. Greenish remarks, "Lobeline has an action closely allied to that of nicotine; it first excites the nerve-cells and then paralyses them." Millspaugh says, "Thanks to much reckless prescribing by many so-called botanic physicians, and to murderous intent, as well as to experimentation and careful provings, the action of this drug is pretty thoroughly known. Lobelia in large doses is a decided narcotic poison, producing effects on animals generally, bearing great similitude to somewhat smaller doses of tobacco, and lobelina in like manner to nicotia."
The prominent symptoms of its action as given by Millspaugh are: "Great dejection, exhaustion, and mental depression, even to insensibility and loss of consciousness; nausea, and vertigo; contraction of the pupil; profuse clammy salivation; dryness and prickling in the throat; pressure in the oesophagus, with a sensation of vermicular motion, most strongly, however, in the larynx and epigastrium; sensation as of a lump in the throat; incessant and violent nausea, with pain, heat, and oppression of the respiratory tract; vomiting, followed by great prostration; violent and painful cardiac constriction; griping and drawing abdominal pains; increased urine, easily decomposing and depositing much uric acid; violent racking paroxysmal cough, with ropy expectoration; small, irregular, slow pulse; general weakness and oppression, more marked in the thorax; violent spasmodic pains, with paralytic feeling, especially in the left arm, weariness of the limbs, with cramps in the gastrocnemi; and sensation of chill and fever. Death is usually preceded by insensibility and convulsions."
Remedy and Means of Control: Professional advice should be obtained immediately.
Being an annual plant, Indian tobacco may be readily destroyed by hand-pulling or grubbing out wherever it is found in small patches. On larger areas, enriching the soil and cultivation will in time choke it out.
The great lobelia (Lobelia syphilitica L.) is suspected of being poisonous. It is native to Ontario, and is found in low grounds.
According to Pammel, the cardinal flower (L.cardinalis L.) found in low grounds in New Brunswick to Ontario, and the spiked lobelia (L. spicata Lam.) another native found in gravelly or sandy soil, from Prince Edward Island to Ontario, have been reported as poisonous.