Unusual name given to one flowering plant (7)
I believe the answer is:
anemone
'flowering plant' is the definition.
(anemone is a kind of flowering plant)
'unusual name given to one' is the wordplay.
'unusual' is an anagram indicator.
'given to' says to put letters next to each other.
'name' with letters rearranged gives 'anem'.
'anem'+'one'='ANEMONE'
(Other definitions for anemone that I've seen before include "Flower; marine polyp" , "Tentacled sea dweller, flower" , "climbing plant" , "Flowering plant - mean one (anag)" , "Plant of the buttercup family with brightly coloured flowers" .)