Related Clues:

• A call to restrict possible source of poison
• A poisonous plant, it comes in a regular shape
• Elbow fans rebuilt plant
• Wolfsbane, or the poison derived from it
• Safe blown in explosion? That's dangerous
• Poisonous plant, one featuring in a short story
• Poisonous plant — it is buried in a geometric shape
• The third 'little pig,' with his house of bricks?