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 opium poppy, Palaver somniferum, Linne (N.O. Papaveraceoe), is probably a native of Asia Minor, but is now cultivated in many warm or temperate countries both as a garden plant and for the sake of its fruits and seeds. The plant is an erect herbaceous annual; it varies very much in the colour of the petals, as well as in the shape of the fruit and colour of the seeds. In England a variety with pale flowers and whitish seeds is cultivated for medicinal use.
The fruits are of a pale glaucous green when young, and exude when wounded a bitter, white, milky juice (latex); as they ripen they change to yellowish brown, and are then cut from the stems. In Germany the unripe fruits are considered to be more active than the ripe.
Poppy heads vary very much both in shape and size. Some varieties are ovoid, others are nearly globular, others again depressed both at the summit and base, the latter variety attaining 8 cm. or more in diameter. The fruit is pale yellowish brown, often marked with darker spots, glabrous, and crowned with the persistent remains of twelve to fifteen stellate, sessile stigmas; below, it is contracted into a neck which is swollen just above the point of attachment to the peduncle and marked there with the scars of the petals and sepals. Cut transversely the fruit is seen to be unilocular, but formed by the union of as many carpels as there are stigmas. From the inner surface of the thin, brittle pericarp, yellowish, membranous placentas, corresponding in number to the carpels, project into the cavity of the fruit.
The seeds, which for the most part lie loose in the fruit, are minute and very numerous. Under a lens they may be seen to be reniform in shape and covered with distinct, delicate reticulations. They vary in colour from whitish to slate (the latter being known as maw seed), and contain an oily endosperm.
Poppy capsules have no odour; the seeds have an oily taste, but the pericarp is distinctly bitter.
The student should observe
(a) The sessile stellate stigmas,
(b) The membranous placentas,
(c) The reniform shape of the seed and the reticulations on its surface.
Poppy capsules contain the principal constituents of opium, the most important of which is the crystalline alkaloid morphine. Ripe capsules have been found to contain 0.018 (Malin,1906), 0-16 (Dieterich), and 0.28 (Paul and Cownley) percent, of morphine; unripe 0.06 (Malin) and 0.086 (Dieterich) per cent.; there is, therefore, some uncertainty as to the actual and the relative medicinal value of ripe and unripe fruits.
Fig. 50. - Poppy capsule, cut vertically. (Planchon and Collin).
Fig. 51. - Poppy seed. Mag-n i f i e d. (Bentley and Tri-men).
Poppy capsules also contain meconic acid, an organic acid found only in the latex of the opium poppy. Although this acid is not an active constituent from a therapeutic point of view, the detection of its presence is often important as indicating a preparation of poppy capsules or of opium.
The seeds are free from morphine, but are said to contain traces of narcotine and amorphous alkaloid; the principal constituent in them is the pale yellow fixed oil (see ' Poppy Oil'); it is a drying oil and is used by artists as well as for culinary and various technical purposes. They occasionally (Russian seeds) contain henbane fruits.
The action of poppy capsules is the same as that of opium, but much weaker. The warm decoction is a favourite anodyne fomentation. The extract and syrup are uncertain remedies, and preparations of opium are in every respect preferable.