A poppy is a flowering plant in the subfamily Papaveroideae of the family Papaveraceae. Poppies are herbaceous plants, often grown for their colourful flowers. One species of poppy, Papaver somniferum, is the source of the narcotic drug opium which contains powerful medicinal alkaloids such as morphine and has been used since ancient times as an analgesic and narcotic medicinal and recreational drug. It also produces edible seeds. Following the trench warfare in the poppy fields of Flanders, Belgium during World War I, poppies have become a symbol of remembrance of soldiers who have died during wartime, especially in the UK, Canada, Australia, New Zealand and other Commonwealth realms.