Supplies of flowers (6)
I believe the answer is:
stocks
I believe this is a double definition.
'supplies' is the first definition.
(stocking is a kind of supplying)
'flowers' is the second definition.
(stock is a kind of flower)
'of' acts as a link.
(Other definitions for stocks that I've seen before include "In which miscreant is locked" , "Old public punishment device" , "Keeps" , "Amounts of goods kept by traders" , "Securities, investments" .)