Floral symbols of purity (6)
I believe the answer is:
lilies
(Other definitions for lilies that I've seen before include "Plants with slender stems and large trumpet-shaped flowers" , "'''Consider the ... of the field, how they grow'' (Bible) (6)'" , "bloomers" , "Luke: ` `Behold the ...... of the field' '" , "Flowering plants" .)