The opium poppy is botanically classified as Papaver somniferum. The genus is named from the Greek noun for a poppy, the species from the Latin word meaning 'sleep inducing': it was Linnaeus, the father of botany, who first classified it in his book Genera Plantarum in 1753. Like many of his contemporaries, and generations before him, he was well aware of its capabilities. The plant has a dubious history. Some horticulturists consider it evolved naturally, but there are others who claim it is a cultivor developed by century upon century of careful human cultivation. Another theory is that it is a naturally mutated plant which evolved because of a quirk of climate or altitude. This is not far-fetched for plants will take on atypical forms in unique conditions: the cannabis trees of Bhutan prove the point. No one can be certain. Although there is no positive proof, it is thought P. somniferum may have evolved, or been generated, either from the wild poppy, Papaver setigerum, which contains small amounts of opium and which indigenously grows throughout the countries bordering the Mediterranean Sea, or from a poppy native to Asia Minor. To many not specifically engaged in its cultivation, the poppy is either an ornamental flower with a delicate beauty or a simple, scarlet blossom growing wild in the cereal fields of Europe, an image for the blood spilled in the trenches of the First World War. In fact, it comes from a large botanical family of 28 genera and over 250 individual species, most of which grow in the temperate and sub-tropical regions of the Northern Hemisphere. Many popular varieties have been specifically cultivated: the bush and tree poppies, the Welsh poppy, the blue and Syrian tulip poppies, the alpine poppy, the sub-arctic Iceland poppy, the Californian poppy. Even the opium poppy itself may be found in borders and displays in well-kept gardens, albeit illegally in most countries. In its wild state, the poppy is a single bloom but double flowers and specialist blooms with serrated and fringed petals have also been bred in a multitude of colours: the most exquisite are two variations of the opium poppy, the Pink Chiffon and the Paeony-flowered Mixed. Several species, such as the Oriental poppy from Asia Minor, are perennials.