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Poisonous Plants

1. Accidental ingestion of poisonous plant

It may be difficult to distinguish poisonous plants from edible plants just by looking at a part of the plant such as new sprouts, young leaves, roots, and berries. When eating collected wild vegetables, you need to be certain to learn their features and how to distinguish them.

Edible plants Poisonous plants easily mistaken for harmless ones Similar parts
Hosta montana, alpine leek Veratrum grandiflorum Young leaves
Burdock (root), sesame (seed) Datura Roots, seeds
Artemisia, sacalia delphiniifolia Aconitum Young leaves
Taro (Colocasia esculenta) Alocasia odora Stems, rhizomes
Chinese chive (leaf), wild garlic(bulb Narcissus Leaves, bulbs
Butterbur sprout Scopolia japonica New sprouts
Star anise Illicium anisatum Berries
Japanese parsley (leaf), Japanese horseradish (wasabi)(rhizome Water-hemlock Leaves, rhizomes
Cirsium dipsacolepis Pokeweed (Phytolacca americana), pokeweed *roots

*Ingredient of commercially available “Japanese pickles of pokeweed” is the root of cirsium dipsacolepis.

2. Food poisoning cases caused by poisonous plants

Occurrence of food poisoning during the past 13 years (2003 to 2015) for which responsible plants were identified or surmised is shown below table;

Plant name Number of incidents Plant name Number of incidents Plant name Number of incidents
Narcissus 43 Arisaema 3 Cyrtanthus 1
Veratrum grandiflorum   42 Scopolia japonica 3 Rhododendron 1
Common bean   33 Gourd 3 Snowflake 1
Datura   30 Glory lily 2 Chinese elder 1
Potato 24 Digitalis 2 White rain lily 1
Aconitum 21 Water-hemlock 2 Eggplant (eggplant is grafted on Angel’s trumpet as a base) 1
Alocasia odora 12 Bottle gourd 2 Symplocarpus nipponicus   1
autumn crocus   11 Rhizome of Calla lily (Taro, Zantedeschia) 1 Japanese wisteria 1
Pokeweed (Phytolacca americana) 5 Carolina jasmine 1 Common vetch  1
Hydrangea 3 Nicotiana glauca  1 Rhododendron japonicum 1

3. Major poisonous substances in plant

While the reason why plants produce poisonous substances has not clearly elucidated, one of the reasons may be protection from being eaten for species preservation.
Specific poisonous substances include nitrogen compounds which are called “alkaloids” and “cyanogen glycoside” with enzymatic action producing cyan.

4. Preventive measures for food poisoning caused by poisonous plants

Please be careful not to develop food poisoning caused by poisonous plants.

Five points for preventing food poisoning caused by poisonous plants

1 Be aware that it is difficult to distinguish types just by looking at new sprouts and roots.
2 Learn accurate knowledge under the guidance of experts.
3 When collecting wild vegetables, be careful that poisonous species do not get mixed in with them.
4 Prepare them correctly (removing scum of bracken or sprouts of potatoes).
5 Do not eat if you are uncertain whether it is edible.

If you are poisoned, please seek medical care immediately.
When doing so, take the poisonous plant that you suspect to be the cause if there is any leftover to the doctor for his/her reference.


Bureau of Public Health, Tokyo Metropolitan Government
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