A concentrate of poppy straw, obtained from a poppy straw of a plant of Papaver somniferum, said plant having a high codeine trait wherein codeine is the predominant alkaloid and in the poppy straw constitutes 40% by weight or greater of the alkaloid combination comprising morphine, codeine, thebaine and oripavine, there being substantially no oripavine or morphine in the alkaloid combination, said plant being obtainable by: crossing a first P. somniferum parent plant containing thebaine with a second P. somniferum parent plant containing morphine, wherein the first P. somniferum plant contains a mutation which prevents thebaine being converted to neopinone and prevents oripavine being converted to morphinone, said mutation being designated "TOP1", and a further mutation blocking the conversion of thebaine to oripavine and also blocking the metabolic step between codeine and morphine, such that the first P. somniferum plant yields poppy straw containing thebaine and has substantially no oripavine, morphine or codeine, and producing an F2 generation of plants by self-pollination of F1 plants obtained from the said cross and selecting plants in the F2 generation containing high contents of codeine, and substantially no oripavine or morphine wherein the selected said plants have said high codeine trait, wherein the TOP1 mutation is from seed deposited under accession number ATCC PTA-9110, and wherein the further mutation is as contained in seed of deposit ATCC PTA-9294. wherein codeine is the predominant alkaloid and in the poppy straw constitutes 40% by weight or greater of the alkaloid combination comprising morphine, codeine, thebaine and oripavine, there being substantially no oripavine or morphine in the alkaloid combination, said plant being obtainable by: crossing a first P. somniferum parent plant containing thebaine with a second P. somniferum parent plant containing morphine, wherein the first P. somniferum plant contains a mutation which prevents thebaine being converted to neopinone and prevents oripavine being converted to morphinone, said mutation being designated "TOP1", and a further mutation blocking the conversion of thebaine to oripavine and also blocking the metabolic step between codeine and morphine, such that the first P. somniferum plant yields poppy straw containing thebaine and has substantially no oripavine, morphine or codeine, and producing an F2 generation of plants by self-pollination of F1 plants obtained from the said cross and selecting plants in the F2 generation containing high contents of codeine, and substantially no oripavine or morphine wherein the selected said plants have said high codeine trait, wherein the TOP1 mutation is from seed deposited under accession number ATCC PTA-9110, and wherein the further mutation is as contained in seed of deposit ATCC PTA-9294. crossing a first P. somniferum parent plant containing thebaine with a second P. somniferum parent plant containing morphine, wherein the first P. somniferum plant contains a mutation which prevents thebaine being converted to neopinone and prevents oripavine being converted to morphinone, said mutation being designated "TOP1", and a further mutation blocking the conversion of thebaine to oripavine and also blocking the metabolic step between codeine and morphine, such that the first P. somniferum plant yields poppy straw containing thebaine and has substantially no oripavine, morphine or codeine, and producing an F2 generation of plants by self-pollination of F1 plants obtained from the said cross and selecting plants in the F2 generation containing high contents of codeine, and substantially no oripavine or morphine wherein the selected said plants have said high codeine trait, wherein the TOP1 mutation is from seed deposited under accession number ATCC PTA-9110, and wherein the further mutation is as contained in seed of deposit ATCC PTA-9294.