Why did McCrae choose poppies as the flowers that grow in Flanders Fields?

McCrae chose poppies as the flowers in "In Flanders Fields" due to their striking red color, which symbolizes the blood shed by soldiers in battle. The poppy's resilience in growing in the war-torn fields of Flanders served as a poignant reminder of both the loss of life and the enduring nature of memory and hope. Additionally, poppies had historical associations with sleep and death, making them a powerful emblem for the fallen soldiers.