The enormous increase in our population has necessitated more and more food production through alternate resources such as mushroom as the availability of more arable land for traditional crops is not likely to increase. In the developed countries, mushrooms have become one of the most important of all the horticultural crops. Mushrooms are being used as food and medicine since time immemorial. Their cultivation on extensive scale can help to solve many problems of global importance such as protein shortage, resource recovery and reuse as well as part of environmental management. The common edible mushroom (Agaricus bisporus) accounts for about 75 per cent of the one million tons of mushroom in the world each year. In this book the author has given detailed description of mushroom Agaricus species collected from different agroclimatic zones of Kerala state along with habitat, seasonal occurrence and their edibility which are inevitable for the exploitation of the flora. Also includes the physiological studies of the collected species. Glossary of the technical terms used in the text is provided.