Small Powdered covered flower buds and Purplish Flowers

The oblong leaves are similar but smaller compared to the Canna Plants and flourish plentifully at the ground near the Lake of Friendship Park. The stalks and flowers are few, swinging slenderly out of the leaves. Very seldom, they flowered, but last week there seemed to be a number. The external surfaces are covered with white powder which is found in Canna buds too. 
Not be able to find the species name.