PAPAVERACEÆ.
PETALA RHŒADOS.
Flores Rhœados; Red Poppy Petals; F. Fleurs de Coquelicot; G. Klatschrosen.
Botanical Origin—Papaver Rhœas L.—The common Red Poppy or Corn Rose is an annual herb found in fields throughout the greater part of Europe often in extreme abundance. It almost always occurs as an accompaniment of cereal crops, frequently disappearing when this cultivation is given up. It is plentiful in England and Ireland, but less so in Scotland; is found abundantly in Central and Southern Europe and in Asia Minor, whence it extends as far as Abyssinia, Palestine, and the banks of the Euphrates. But it does not occur in India or in North America.
From the evidence adduced by De Candolle[176] it would appear that the plant is strictly indigenous to Sicily, Greece, Dalmatia, and possibly the Caucasus.
History—Papaver Rhœas was known to the ancients, though doubtless it was often confounded with P. dubium L. the flowers of which are rather smaller and paler. The petals were used in pharmacy in Germany in the 15th century.[177]
Description—The branches of the stem are upright, each terminating in a conspicuous long-stalked flower, from which as it opens the two sepals fall off. The delicate scarlet petals are four in number, transversely elliptical and attached below the ovary by very short, dark violet claws. As they are broader than long, their edges overlap in the expanded flower. In the bud they are irregularly crumpled, but when unfolded are smooth, lustrous, and unctuous to the touch. They fall off very quickly, shrink up in drying, and assume a brownish-violet tint even when dried with the utmost care. Although they do not contain a milky juice like the green parts of the plant, they have while fresh a strong narcotic odour and a faintly bitter taste.
Chemical Composition—The most important constituent of the petals is the colouring matter, still but very imperfectly known. According to L. Meier (1846) it consists of two acids, neither of which could be obtained other than in an amorphous state. The colouring matter is abundantly taken up by water or spirit of wine but not by ether. The aqueous infusion is not precipitated by alum, but yields a dingy violet precipitate with acetate of lead, and is coloured blackish-brown by ferric salts or by alkalis.
The alkaloids of opium cannot be detected in the petals. Attfield in particular has examined the latter (1873) for morphine but without obtaining a trace of that body.
The milky juice of the herb and capsules has a narcotic odour, and appears to exert a distinctly sedative action. Hesse obtained from them (1865) a colourless crystallizable substance, Rhœadine, C₂₁H₂₁NO₆, of weak alkaline reaction. It is tasteless, not poisonous, nearly insoluble in water, alcohol, ether, chloroform, benzol, or aqueous ammonia, but dissolves in weak acids. Its solution in dilute sulphuric or hydrochloric acid acquires after a time a splendid red colour, destroyed by an alkali but reappearing on addition of an acid. Hesse further believes (1877) the milky juice to contain meconic acid.