Bloomer by Albert, a novel sleuth (7)
I believe the answer is:
campion
'bloomer' is the definition.
(campion is a kind of flowering plant)
'albert a novel sleuth' is the wordplay.
I cannot quite understand how this works, but
'a' is found in the answer.
'sleuth' could be 'pi' and 'pi' is present in the answer.
This explanation may well be incorrect...
'by' acts as a link.
Can you help me to learn more?
(Other definitions for campion that I've seen before include "Plant with pink or white flowers" , "Wild flower (red, white or bladder)" , "Film director" , "Here's one blooming" , "Edmund ---, martyr; Thomas ---, poet/lute composer" .)