Ramson leaves can be confused with poisonous plants

Apr 30 2012

The National Food Institute, Technical University of Denmark has assessed the possible toxic effects of eating ramson, which in recent years has become a popular plant to gather and eat in Denmark. As such, ramson does not contain any substances that are toxic for humans, but they can be confused with poisonous plants. In particular, before flowering, ramson leaves can be confused with autumn crocus and lily of the valley. Several cases of poisoning have been reported in other European countries with fatal consequences as a result of this confusion.

Ramson (Allium ursinum L.) has for a long time been used abroad, but new Nordic cuisine in particular has made ramson gathering in Denmark a popular activity. Ramson grows wild in both Denmark and in several other European countries. In many, primarily central European countries, there is a tradition for picking ramson in the wild and using the leaves in salads, as a culinary herb or boiled and served as a vegetable.

Natural is not synonymous with safe
"Many believe that plants are healthy and unharmful just because they come from nature, but this is not always the case. The plants which ramsons can be confused with contain substances which are potentially harmful and even lethal for humans," says Kirsten Pilegaard, Senior adviser at the National Food Institute, Technical University of Denmark.

As such, ramson does not contain any substances that are toxic for humans. In reviewing the literature on the subject, the National Food Institute has found no descriptions of people being poisoned after consuming correctly identified ramson leaves. However, ramson leaves can be confused with poisonous plants such as autumn crocus and lily of the valley especially when the leaves are picked before the plants flower. Ramson and lily of the valley flower in the spring, while, as its name implies, autumn crocus flowers in the autumn.

Plant gathering requires botanical knowledge
"People confusing ramson with poisonous plants such as autumn crocus and lily of the valley often lack sufficient knowledge about the plants they gather. Most people know that gathering fungi requires a certain amount of knowledge in order to correctly identify the individual fungi. Gathering plants requires botanical knowledge to make sure you do not pick a poisonous plant", says Kirsten Pilegaard.

Autumn crocus grows wild in, for example, central Europe. In Denmark, it is grown as a garden plant. It is rarely found in the wild in Scandinavia, but can run wild from gardens. Lily of the valley is both grown in gardens and grows wild in Denmark.

"It has been mentioned that it is possible to find ramson in parks and cemeteries. It is, however, important to be aware that there is a greater risk of not only finding ransom but for example also autumn crocus here than in the open countryside," says Kirsten Pilegaard.

Fatal cases of poisoning abroad
In a German study of 32 cases of poisoning where leaves from autumn crocus were eaten instead of ramson leaves, six of the poisoned people died. In three of the severe cases, the victims suffered from pulmonary oedema, kidney failure, acute liver failure and complete unconsciousness, in six cases of medium severity people experienced liver failure, violent vomiting and diarrhoea and muscular pains and damage while 17 victims suffered from lighter symptoms like nausea, light cases of vomiting and diarrhoea. The National Food Institute is not aware of any Danish cases of poisoning. 

"The literature shows that the poisoned people more often suffer from severe poisoning when heating the autumn crocus leaves. "If the leaves were eaten raw, 30% of cases suffered medium or severe poisoning, while 64% developed these symptoms after eating leaves which had been heated", says Kirsten Pilegaard.

Cases of poisoning where ramson was confused with lily of the valley have not yet resulted in fatalities. The poisoned people suffered from symptoms such as nervousness, headache, hallucinations and skin symptoms after intake of lily of the valley.