Plant with flowers — double the number in miraculous wedding location (5)
I believe the answer is:
canna
'plant' is the definition.
(canna is a kind of plant)
'number in miraculous wedding location' is the wordplay.
'number' becomes 'c' (C is an example).
'in miraculous wedding location' becomes 'anna' (I can't explain this - if you can you should give a lot more credence to this answer).
'c'+'anna'='CANNA'
'with flowers double the' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for canna that I've seen before include "Lily-like plant" , "in Scotland is unable to" , "Kind of lily" , "Showy tropical plant" .)