200 HERBS 



LOBELIA 



(Herba Lobelias) 



Source, &c. Lobelia or Indian tobacco, Lobelia inflata, Linn 6 (N.O. 

 Campanulacecp), an erect annual herb with acrid milky juice (latex), 

 is distributed over the eastern States of North America, and cultivated 

 for medicinal use in the States of New York and Massachusetts. The 

 drug was a domestic medicine of the North American Indians, and 

 was introduced into European practice about 1830. The plant is cut 

 as soon as the lower capsules turn brown, and dried ; it is sent into 

 commerce either in bales or in oblong compressed packets. 



Description. The stem of the plant, which varies in colour from 

 green to yellowish or often purplish, is hairy and winged in the upper 

 part, but quadrangular, channelled, and nearly glabrous below. The 

 leaves are alternate, broadly oval to ovate-lanceolate in outline, and 

 vary in length from about 3 to 8 cm. They are sessile or shortly 

 petiolate, and bear, especially on the veins of the under surface, 

 scattered bristly hairs ; the margin is irregularly crenate-dentate. 



The flowers, which are arranged in a long leafy raceme, have a pale 

 blue bilabiate corolla, a tubular calyx with five long spreading teeth and 

 an inferior two-celled ovary. The latter develops into an ovoid, inflated, 

 ten-ribbed fruit, about 7 or 8 mm. long, crowned with the remains 

 of the calyx, and containing numerous minute, brown, oval-oblong 

 seeds, which, under the lens, exhibit a beautifully reticulated surface. 



In the commercial drug the green hairy and winged or purplish and 

 channelled stems with alternate leaf-scars are easily found. The 

 leaves are mostly in a fragmentary condition, but recognisable by 

 their hairy under surface. The flowers are seldom to be found, but 

 the characteristic inflated fruits containing the very minute seeds are 

 always present. 



The stems and leaves contain laticiferous vessels in the bast, a 

 character that can be ascertained by microscopical examination only, 

 but one that may afford valuable aid in identifying doubtful specimens. 



The drug has a somewhat irritant odour, and, when chewed, an 

 unpleasant acrid burning taste. 



It is said that the plants are sometimes allowed to mature their 

 seeds and are then thrashed, the seeds being sold separately, whilst 

 the herb is pressed into packets. This would account for the frequent 

 absence of the flowers from the drug, and for the presence of numerous 

 capsules but comparatively few ripe seeds. 



The student should observe 



(a) The hairy winged stem, 



(b) The inflated fruits, 



(c) The minute oblong reticulated seeds. 



