Opium is a narcotic resin produced from opium poppies (Papaver somniferum). It contains up to 16% morphine, an opiate alkaloid, which is most frequently processed chemically to produce heroin for the black market. The resin also has non-narcotic alkaloids in it. Some of these are papaverine and noscapine. Opium is also known as afeem, and was called "God's Own Medicine" during its time of greatest popularity. It can be yellow or dark brown, and has a bitter taste.