A dozen primary school pupils needed hospital treatment after eating a daffodil bulb in a cookery class, a Suffolk council has said.
The children, from Gorseland Primary School in Martlesham Heath, fell ill after mistakenly adding the bulb to a soup on Friday.
Daffodil bulbs are poisonous and can be fatal if eaten in large quantities.
The pupils were taken to Ipswich Hospital, but were allowed home later, said Suffolk County Council.
A council spokesman said: "A class of 30 children from Gorseland Primary School were making soup, using onions from their own kitchen garden.
"Unfortunately, a daffodil bulb was used by mistake, making a number of the children sick.
"The school immediately called NHS Direct and the children's parents.
"An incident team was rushed to the school and 12 children were taken to Ipswich Hospital as a precautionary measure but were allowed home later in the afternoon."