This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
The official Datura leaves are the dried leaves of D. fastuosa, Linne, var. alba, Nees, and also of D. Metel, Linne, annual plants indigenous to India where the leaves are used as an equivalent of belladonna and thornapple. They are brownish or yellowish green, ovate, acuminate, sinuate-dentate, often unequal at the base, up to 20 cm. long and 12.5 wide, with long petioles. The odour is characteristic and unpleasant; taste bitter. The epidermis bears scattered simple hairs and stalked glandular hairs.
They contain about 0'5 per cent, of alkaloid, chiefly scopolamine (hyoscine) with traces of hyoscyamine and atropine. They serve as a commercial source of scopolamine.
Datura Tatula, Linne, is a variety of D. Stramonium with a violet corolla and purplish veins; the leaves are used together with stramonium leaves for making asthma cigarettes.