Brock Cantillo was poisoned by Walt in an unknown way with the Lily of the Valley berry.The doctors initially thought Brock was poisoned by ricin as Jesse Pinkman had suggested but later discovered the true toxin. The doctors and Jesse believed that Brock came across the flower growing naturally and ate some poisonous berries. ("")
After returning home from successfully getting Hector Salamanca to kill Gus and getting Jesse back on his side, Walt disposed of the Lily plant from his backyard. ("")
- The symptoms associated with lily of the valley poisoning are somewhat similar to ricin poisoning, but far less severe, as so far no deaths from consumption of lily of the valley have been confirmed.
- The plant contains at least 38 cardiac glycosides, all which are known to be harmful, with convallatoxin and convallamarin being the majority components.
- Lily of the Valley at Wikipedia