Why is the Blessed Mother often in pictures with flowers?

In icons and often in religious paintings, all the items tell something about the thing being depicted.  For example, the number of items can indicate something; the color of an item can indicate something; and even the flowers can indicate something.  There are special flowers especially associated with the Blessed Mother.  For example:  the violet is also known in some places as "Our Lady's Modesty."  It is associated with her humility.  The lily of the valley is known as "Mary's Tears."  It reminds us of her sorrow as the death of her Son.  The hawthorn is known as "Mary's flower of May."  Lilies represent purity.  The Rose is often depicted with her because the word Rosary means 'rose garden' and of course she gave us a garden full of prayers when she taught us the rosary.