What does the word poppy in this passage refer to?

November is poppy month, the time of the year when we wear a red poppy in memory of those who sacrificed their lives for us during wars. But how many of us are aware of the reason of how and why the poppy became the symbol of remembrance and an integral part of the work of the Royal British Legion? Flanders is the name of the whole western part of Belgium. It saw some of the most concentrated and bloodiest fighting of the First World War. Where once there were homes and farms there was now a sea of mud--a grave for the dead where men still lived and fought.  Only one other living thing survived. The poppy flowering each year with the coming of the warm weather, brought life, hope, colour and reassurance to those still fighting. John McCrae, a doctor serving with the Canadian Armed Forces, was so deeply moved by what he saw in northern France that, in 1915 in his pocket book, he scribbled down the poem "In Flanders Fields". The poppy became a popular symbol for soldiers who died in battle. In 1918, Moira Michael, an American, wrote a poem in reply, "We shall keep the faith", in which she promised to wear a poppy "in honour of our dead". This began the tradition of wearing a poppy in remembrance.