Poppies are herbaceous plants(草本植物), often grown for their colorful flowers. One species of poppy, Papaver somniferum, is the source of the crude drug opium which contains powerful medicinal alkaloids such as morphine and has been used since ancient times as an analgesic(鎮痛性の)and narcotic medicinal and recreational drugs. It also produces edible seeds. Following the trench warfare which took place in the poppy fields of Flanders, during the 1st World War, poppies have become a symbol of remembrance of soldiers who have died during wartime.