Plant notice: "No men allowed around stores" (7)
I believe the answer is:
anemone
'plant' is the definition.
(anemone is a kind of plant)
'notice no men allowed around stores' is the wordplay.
'stores' says the answer is hidden in the clue.
'around' shows that the letters should be reversed in order.
'enomena' is hidden in the letters of 'notice no men allowed'.
'enomena' written backwards gives 'ANEMONE'.
(Other definitions for anemone that I've seen before include "White woodland flower" , "Plant of the buttercup family with brightly coloured flowers" , "Plant; sea creature" , "Plant of the buttercup family - one name (anag)" , "Sea plant or garden flower" .)