Papaver somniferum, commonly known as the opium poppy or breadseed poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable ornamental plant grown in gardens. Its native range is the western Mediterranean region, but has since been obscured by widespread introduction and cultivation since ancient times to the present day. It is now naturalised across much of the world with temperate climates.

Description Papaver somniferum is an annual herb growing to about tall. The plant is strongly glaucous, giving a greyish-green appearance, and the stem and leaves bear a sparse distribution of coarse hairs. The large leaves are lobed, the upper stem leaves clasping the stem, the lowest leaves with a short petiole. The flowers are up to diameter, normally with four red, white, or mauve petals, often with a dark patch at the base of each petal. The fruit is a hairless, rounded capsule topped with 12–18 radiating stigmatic rays, or fluted cap. All parts of the plant exude white latex when wounded.

Distribution and habitat The native range of opium poppy is probably Macaronesia, W. & Central Mediterranean , but extensive cultivation and introduction of the species throughout Europe since ancient times have obscured its origin. It has escaped from cultivation, or has been introduced and become naturalised extensively in all regions of the British Isles, particularly in the south and east, with its seeds having been found in archaeological material dating back to the Bronze Age and in almost all other countries of the world with suitable, temperate climates.

Taxonomy Papaver somniferum was given its accepted name by the Swedish botanist Carl Linnaeus on page 508 of his Species Plantarum in 1753. It is classified in the genus Papaver within the larger family Papaveraceae. It has two accepted subspecies and one natural hybrid between them:

Papaver somniferum nothosubsp. authemaniiThis natural hybrid is native to France. It was first described as a hybrid named Papaver × authemanii in 1893 and reclassified to its accepted name in 2012. Papaver somniferum subsp. setigerumThis subspecies was first named Papaver setigerum in 1815 by Augustin Pyramus de Candolle. It was reclassified as a subspecies in 1882 by Giovanni Arcangeli. Its native range is North Africa from Morocco to Lybia and in southern Europe from Portugual to Italy. Papaver somniferum subsp. somniferum The autonymic subspecies is a cultigen, a plant that has been developed by human selection.

The opium poppy has synonyms of its two subspecies and the hybrid.

Table of Synonyms Name Year Rank Synonym of: Notes Papaver album 1768 species subsp. somniferum = het. Papaver album-nigrum 1763 species subsp. somniferum = het. Papaver amoenum 1839 species subsp. somniferum = het. Papaver amplexicaule 1812 species subsp. somniferum = het. Papaver apodocarpum 1835 species subsp. somniferum = het. Papaver × authemanii 1893 hybrid nothosubsp. authemanii ≡ hom. Papaver glabrum 1782 species subsp. somniferum = het., opus utique oppr. Papaver glaucum var. leucum 1954 variety subsp. somniferum = het. Papaver hortense 1835 species subsp. somniferum = het. Papaver hortense 1764 species subsp. somniferum = het., opus utique rej. Papaver indehiscens 1827 species subsp. somniferum = het. Papaver nigrum 1764 species subsp. somniferum = het., opus utique rej. Papaver nigrum 1845 species subsp. somniferum = het. Papaver officinale 1806 species subsp. somniferum = het. Papaver officinale var. monstrosum 1851 variety subsp. somniferum = het. Papaver opiiferum 1775 species subsp. somniferum = het. Papaver opiiferum var. album 1821 variety subsp. somniferum = het. Papaver paeoniiflorum 1926 species subsp. somniferum = het. Papaver polycephalum 1863 species subsp. somniferum = het. Papaver setigerum 1815 species subsp. setigerum ≡ hom. Papaver setigerum var. muticum 1856 variety subsp. setigerum = het. Papaver setigerum var. nigrum 1936 variety subsp. somniferum = het. Papaver setigerum var. valdesetosum 1935 variety subsp. setigerum = het. Papaver somniferum var. album 1821 variety subsp. somniferum = het. Papaver somniferum f. album 1887 form subsp. somniferum = het. Papaver somniferum convar. album 1866 convariety subsp. somniferum = het. Papaver somniferum var. apodocarpum 1866 variety subsp. somniferum = het. Papaver somniferum var. atroviolaceum 1934 variety subsp. setigerum = het. Papaver somniferum subvar. atroviolaceum 1964 subvariety subsp. setigerum = het. Papaver somniferum var. austroviolaceum 1975 variety subsp. somniferum = het. Papaver somniferum var. caesium 1866 variety subsp. somniferum = het. Papaver somniferum var. coccineum 1932 variety subsp. setigerum = het. Papaver somniferum var. dinocarpum 1866 variety subsp. somniferum = het. Papaver somniferum f. dissectum 1887 form subsp. somniferum = het. Papaver somniferum convar. drogist 1975 convariety subsp. somniferum = het. Papaver somniferum var. genuinovilaceum 1975 variety subsp. somniferum = het. Papaver somniferum var. glabrum 1867 variety subsp. somniferum = het. Papaver somniferum var. griseum 1866 variety subsp. somniferum = het. Papaver somniferum var. haageanum 1866 variety subsp. somniferum = het. Papaver somniferum subsp. hortense 1882 subspecies subsp. somniferum = het. Papaver somniferum subsp. hortense 1863 subspecies subsp. somniferum = het. Papaver somniferum var. hortense 1866 variety subsp. somniferum = het. Papaver somniferum var. hortense 1893 variety subsp. somniferum = het. Papaver somniferum var. hussenotii 1866 variety subsp. somniferum = het. Papaver somniferum convar. indicum 1975 convariety subsp. somniferum = het., without type. Papaver somniferum f. laciniatum 1887 form subsp. somniferum = het. Papaver somniferum var. leucum 1987 variety subsp. somniferum = het. Papaver somniferum var. luteum 1866 variety subsp. somniferum = het. Papaver somniferum f. marginatum 1887 form subsp. somniferum = het. Papaver somniferum monstrosum 1860 subsp. somniferum = het. Papaver somniferum subsp. nigrum 1834 subspecies subsp. somniferum = het., nom. illeg. Papaver somniferum subsp. nigrum 1908 subspecies subsp. somniferum = het. Papaver somniferum var. nigrum 1821 variety subsp. somniferum = het. Papaver somniferum f. nigrum 1887 form subsp. somniferum = het. Papaver somniferum convar. nigrum 1866 convariety subsp. somniferum = het. Papaver somniferum subsp. officinale 1894 subspecies subsp. somniferum = het. Papaver somniferum var. officinale 1866 variety subsp. somniferum = het. Papaver somniferum proles officinale 1893 proles subsp. somniferum = het. Papaver somniferum convar. opiiferum 1975 convariety subsp. somniferum = het. Papaver somniferum subsp. opiiferum 1914 subspecies subsp. somniferum = het. Papaver somniferum var. paeoniiflorum 1866 variety subsp. somniferum = het. Papaver somniferum f. poecilospermum 1887 form subsp. somniferum = het. Papaver somniferum convar. poecilospermum 1866 convariety subsp. somniferum = het. Papaver somniferum var. pullatum 1975 variety subsp. somniferum = het. Papaver somniferum var. quassandum 1866 variety subsp. somniferum = het. Papaver somniferum var. roseum 1866 variety subsp. somniferum = het. Papaver somniferum var. rubellum 1975 variety subsp. somniferum = het. Papaver somniferum var. setigerum 1836 variety subsp. setigerum ≡ hom. Papaver somniferum proles setigerum 1893 proles subsp. setigerum ≡ hom. Papaver somniferum var. stipitatum 1866 variety subsp. somniferum = het. Papaver somniferum convar. tarbagataicum 1975 convariety subsp. somniferum = het. Papaver somniferum f. tricolor 1887 form subsp. somniferum = het. Papaver somniferum var. valdesetosum 1964 variety subsp. setigerum = het. Papaver somniferum var. violiflorum 1975 variety subsp. somniferum = het. Papaver stipitatum 1835 species subsp. somniferum = het. Papaver sylvestre 1854 species subsp. somniferum = het. Notes: ≡ homotypic synonym ; = heterotypic synonym

Uses This poppy is grown as an agricultural crop on a large scale, for one of three primary purposes; to produce poppy seeds, to produce opium for use mainly by the pharmaceutical industry, and to produce other alkaloids (mainly thebaine and oripavine) that are processed by pharmaceutical companies into drugs such as hydrocodone and oxycodone. Each of these goals has special breeds that are targeted at one of these businesses, and breeding efforts (including biotechnological ones) are continually underway. A comparatively small amount of P. somniferum seed is also produced commercially for ornamental purposes.

Today many cultivars have been bred that do not produce a significant quantity of opium. The cultivar 'Sujata' produces no latex at all. This differentiation has strong implications for legal policy surrounding the growing of the plant.

Biology Metabolism The alkaloids are organic nitrogenous compounds, derivatives of secondary metabolism, synthesised through the metabolic pathway of benzylisoquinoline. First, the amino acid phenylalanine, through the enzyme phenylalanine hydroxylase, is transformed into tyrosine. Tyrosine can follow two different routes: by tyrosine hydroxylase it can form L-dopamine (L-DOPA), or it can be reduced to form 4-phenylhydroxyacetaldehyde (4-HPAA). Subsequently, L-DOPA reacts with 4-HPAA and, through a series of reactions, forms (S) -norcoclaurine, which carries the benzylisoquinoline skeleton that gives its name to this pathway. The conversion of (S) -norcoclaurin to (S) -reticuline is one of the key points, since from (S) -reticuline morphine can be formed through the morphinan route, noscapine through the path of the noscapina or berberina.

Genome The poppy genome contains 51,213 genes encoding proteins distributed 81.6% in 11 individual chromosomes and 18.4% remaining in unplaced scaffolds. In addition, 70.9% of the genome is made up of repetitive elements, of which the most represented are the long terminal repeat retrotransposons. This enrichment of genes is related to the maintenance of homeostasis and a positive regulation of transcription.

The analysis of synergy of the opium poppy reveals traces of segmental duplications 110 million years ago (MYA), before the divergence between Papaveraceae and Ranunculaceae, and an event of duplication of the complete genome makes 7.8 MYA.

The genes are possibly grouped as follows:

The genes responsible for the conversion of (S) -reticuline to noscapine are found on chromosome 11. The genes responsible for the conversion of (S) -reticuline to thebaine are found on chromosome 11. The genes responsible for the conversion of thebaine are found in chromosome 1, chromosome 2, chromosome 7, and perhaps others.

Cultivars P. somniferum has had a very long tradition of use, starting in the Neolithic. This long period of time allowed the development of a broad range of different forms. In total there are 52 botanical varieties. Breeding of P. somniferum faces a challenge caused by the contradictory breeding goals for this species. On one hand a very high content of alkaloids is requested for medical uses. Global demand for the alkaloids and their pharmaceutical derivatives has increased in recent years. Therefore, there is a need for the development of cultivars with a high opium yield. On the other hand, the food industry demands alkaloid contents be as low as possible.

There are also many ornamental cultivars selected for colour or number of their petals or other characteristics. There are double-flowered cultivars, often called peony flowered or 'paeoniflorum' in a range of colours. There are even varieties selected for the shape of their pods such as 'Hen and Chickens' with smaller pods around a larger central pod.

Ecology Diseases