Page 107 - Pharmacognosy 2 PG303 (1)

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

LOBELIA HERB

(Asthma weed, Indian tobacco, American Lobelia)

Lobelia is the dried aerial parts of Lobelia inflata L. family Companulaceae, Collected
towards the end of the flowering stage.

It is an annual herb indigenous to eastern USA and Canada and Cultivated in Holand and
USA. It yields not less than 0.25% of total alkaloids calc. as lobeline.

Macroscopical Characters
Stems: are green to yellowish with large purplish patches, angular, winged and very hairy
in the upper part but becoming more rounded, channeled and nearly glabrous below. Leaves: are
pale green in color, alternate, usually more or less broken with scattered stiff hairs especially along
the margin and veins on the lower surfaces. The lower leaves are oblong, shortly petiolate, up to 9
cm Long. The upper leaves are smaller, oval to lanceolate in shape, sessile with irregularly crenate-
dentate margin, each tooth ends in a yellowish- brown swollen apex (water pores). Flowers: are
shortly pedicellate, arranged in long racemes, pale blue about 7 mm. long; calyx, tubular with 5
long linear teeth; corolla: tubular, bilabiate, the posterior lip with 2 erect lobes and cleft nearly to
the base, the anterior lip with 3 spreading lobes; stamens, with blue anthers, united above, forming

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