Diana who sings about English flowers (5)
I believe the answer is:
roses
'flowers' is the definition.
(rose is a type of flower)
'diana who sings about english' is the wordplay.
I cannot really understand how this works, but
'english' could be 'e' (abbreviation) and 'e' is present in the answer.
The remaining letters 'ross' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for roses that I've seen before include "Red, white war symbols" , "Occupants of bed" , "chocolates" , "Bloomers" , "the wars" .)