Bloomer is miserable clanger (8)
I believe the answer is:
bluebell
'bloomer' is the definition.
(bluebell is a kind of flowering plant)
'miserable clanger' is the wordplay.
'miserable' becomes 'blue'.
'clanger' becomes 'bell' (something which clangs).
'blue'+'bell'='BLUEBELL'
'is' acts as a link.
(Other definitions for bluebell that I've seen before include "girl in 1930s dance troupe?" , "The wood hyacinth in S England" , "Perennial" , "Pretty flower with azure chime?" , "Scottish flower" .)