Unfortunately, some poisonous varieties look so similar to edible ones that only experts can tell the difference - and perhaps only by studying the colour of their spores.

In December 2006, sixteen diners were hospitalized after eating a poisonous variety of boletus mushrooms in Beijing at the Dayali Roast Duck Restaurant.

There are many poisonous varieties, and distinguishing one from another is a job for an expert.

On the walk, participants will learn the proper techniques for identifying plant habitats, collecting, harvesting and preparing edible plants and how to distinguish them from poisonous varieties.

They were bred into larger, more poisonous varieties, and were kept as pets.

When the letters being written with it are of the poisonous variety.

A man could live on native food, if he avoided the poisonous varieties; but he must take the dietary capsules the Merseians had prepared.

(Indeed, the poisonous varieties were a favorite of the Borgias.)

Women processed the poisonous variety of cassava by squeezing it to extract the toxic juices.

"I thought witches only offered apples of the poisonous variety," he murmured.