Each of them is a bit of a bloomer (7)
I believe the answer is:
anthers
'each of them' is the definition.
I can't tell whether this defines the answer.
'a bit of a bloomer' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is located in the answer.
This explanation may well be incorrect...
'is' is the link.
Can you help me to learn more?
(Other definitions for anthers that I've seen before include "Pollen containers" , "Parts of flowers that produce the pollen" .)