Presents an introduction to the diversity of macrofungi found in the tropical oak forests of Costa Rica's Talamanca mountain range. Within the guide, 101 species in 10 families are described and illustrated in color, some of which have never been illustrated before. Combining research from the last ten years, Halling and Mueller have concentrated on the collection, description, and documentation of mushrooms that occur naturally in Talamanca's tropical montane wet forests. The species that are emphasized are ones the authors encountered routinely or which are particularly outstanding in appearance.