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 red or field poppy, Palaver Rhoeas, Linne (N.O. Papaveraceoe), is a common herb, doubtfully indigenous to England, but abundant in cornfields and waste places throughout Europe and long used as a medicine. It is the commonest British poppy, and is distinguished by its rich scarlet petals and glabrous, nearly globular fruit.
The long-headed poppy; P. dubium, Linne, is also common, but is generally smaller, more slender, and possesses a capsule often twice as long as it is broad.
The two hairy sepals of the bud fall off as the four delicate crumpled petals expand. The latter are of a bright scarlet colour, with a short, dark violet claw, they are smooth and shining, broadly elliptical, with an entire margin. They have, when fresh, an unpleasant heavy odour and slightly bitter taste. By drying, the bright scarlet colour changes to a dingy violet, and the petals, which are used on account of the colouring matter they contain, are therefore official in the fresh state only.
The colour of the petals is due, in part at least, to mekocyanin, probably present in combination with an acid (see p. 65). The presence of meconic acid, an important constituent of opium, has not yet been definitely ascertained. In the juice of the capsules and herb Hesse found the alkaloid rhoeadine, which is also contained in opium; and it is worth noting that this alkaloid, when decomposed with hydrochloric acid, yields a red colouring matter of intense colorific power. Dieterich (1888) reported the drug to contain 0.1 to 0.7 per cent, of morphine, but according to Hesse and others it is quite free from morphine, Dieterich's alkaloid being rhoeadine.
The petals of the P. dubium contain a toxic alkaloid, aporeine, resembling thebaine in its action, and they should therefore be rejected.
Red poppy petals are employed solely as a colouring agent, chiefly in the form of syrup.
Fig. 36. - Red Poppy. (Planchon and Collin).