Bit of a bloomer by both blokes! (5)
I believe the answer is:
sepal
'bit of a bloomer' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for sepal that I've seen before include "flowery bit" , "Part of a flower's outer envelope" , "part of leaf" , "Calyx segment" , "Part of a flower casing" .)