Put up around one pound for bulb (5)
I believe the answer is:
tulip
'for bulb' is the definition.
(I've seen this before)
'put up around one' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'around' is an insertion indicator.
'one' becomes 'li' (I've seen this in other clues**).
'put' back-to-front is 'tup'.
'tup' placed around 'li' is 'TULIP'.
'pound' is the link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tulip that I've seen before include "Flower - lit up (anag)" , "Garden flower from bulb" , "Spring-flowering plant" , "Dutch export" , "Flowering bulb (from Amsterdam?)" .)