Home Office permission was required to create the poison garden
A garden in Northumberland has appealed for help in finding a deadly killer plant to add to its collection.
The poison garden at Alnwick Castle already grows cannabis, coca and opium and is now seeking a strychnine plant.
As it is not a botanical garden, there are no facilities to grow it from seed so a cutting or mature plant is needed.
The team has discovered only one source of the plant in the UK but it is infested with the pest Chilean thrips and in quarantine.
Alison Hamer, from the Alnwick Garden, said: "The poison garden is one of our most popular attractions and is world-famous for growing cannabis and opium.
"Given strychnine's reputation as a deadly killer, we very much want to include it."
The toxic plant can cause muscular convulsions, spasms and eventual death through asphyxia.
The Duchess of Northumberland was given Home Office permission to create the poison garden, which is kept under 24-hour surveillance and only used for guided tours.
Ms Hamer described it as a unique facility.
"It has a very powerful message about the dangers of plants, and drugs," she said.
"The addition of strychnine is a logical next step and would complete our lethal collection.
"Now that we have exhausted all options, launching an appeal for help seemed to be the only solution."