Possible Clues:

• Growth seen when ship's bottom is turned over
• Edible plant, Welsh symbol
• Staffordshire emblem?
• Turn bottom upwards for Wales
• Vegetable of the onion family
• Sounds as if the water is getting in enough to make the ship turn bottom up
• Staffs emblem?
• National emblem embodying general and king
• Vegetable symbol of Wales
• It was for Wales to have made it turn bottom upwards