Symbol Analysis
Flowers and love poems pretty much go hand-in-hand. "The Blessed Damozel" luckily has a bit more to offer than the "roses are red" routine, though. Here, flowers are important symbols of the condition of the damsel herself.
For example, when we're first introduced to her, we see that, "She had three lilies in her hand" (5). This reminds us of her piety and connection to the Christian Trinity of the Father, the Son, and the Holy Spirit. We also see that she's got a flower on her robe. It's "a white rose of Mary's gift,/ For service meetly worn" (10). The white color of the rose here symbolizes the damozel's purity. That the flower was a gift from Mary in recognition of the damsel's service also shows us that she's a woman who is faithful and pure of heart.
It's not all a bed of roses, though—white, red, or otherwise. Later in the poem, the damsel is surrounded by the souls of reunited lovers. Since her main squeeze is waiting back on Earth, this naturally bums her out. It also, symbolically, wilts her lilies, which "lay as if asleep/ Along her bended arm" (47-48). Just as they represented her purity and devotion, the flowers now reflect her flagging spirit—bad times.