Garlic cousin (4)
I believe the answer is:
leek
'garlic cousin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for leek that I've seen before include "Vegetable emblem of Wales" , "Edible plant, Welsh symbol" , "Vegetable - Welsh emblem" , "National emblem of Wales." , "Welsh national symbol" .)