Book excerpt: A new approach to identifying mushrooms based on five key features that can be observed while in the field. Toadstools, truffles, boletes and morels, witches' butter, conks, corals, puffballs and earthstars: mushrooms are both mysterious and ecologically essential. They can also be either delicious or deadly. Thousands of different species of mushrooms appear across North America in the woods, backyards, and in unexpected corners. Learning to distinguish them is a rewarding challenge for a naturalist or chef. Covering most of the common edible and poisonous species readers are likely to encounter, this portable-sized field guide takes a new, simple approach to the method of mushroom identification based on key features that do not require a microscope or technical vocabulary. In addition to the watercolors from the original edition, hundreds more illustrations have been added. These paintings make use of the limited space available in a field guide and focus on the distinguishing details of each species, thereby serving as an ideal tool for beginner and intermediate mycologists alike.