Gourmet mushrooms may contribute to the development of a new agriculture by addressing the consumer demand and some of the non-nutritional uses of agricultural productions. The value of recycling with gourmet and medicinal mushrooms is clearly understood and wastes can be viewed as positive products, at least in term of providing new economic opportunities and positive environmental consequences. Important cultivated edible and medicinal mushrooms are members of the Agaricus genus. They are saprophytic fungi acting as secondary decomposers in forest litter. The button mushroom is Agaricus bisporus cultivated as a gourmet mushroom since the 18th century and high yields are now obtained in sophisticated farms in western countries. Its potential as a medicinal mushroom has recently been shown. Throughout the world the cultivation of this mushroom is developing in small and mid-sized farms, but the technical knowledge and the strains have been developed for cultivation in high-tech large farms. Needs for small-scale farming are simple cultivation processes using rustic strains able to fruit under various conditions, and strains with stable contents in active ingredients, whatever the cultivation conditions. By using available biodiversity and breeding, one can expect to develop homogeneous, vigorous and rustic strains with good productivity and commercial quality. Potentials are explored in this article.