XVI International Botanical Congess

Intensive surveys encompassing all putative micro- habitats for myxomycetes were carried out in Puerto Rico, Costa Rica, and Ecuador. Describing all micro- habitat features, about 2400 specimens were collected in the field, and an additional 1300 were obtained from 1500 substrate samples cultured in moist chambers. A preliminary evaluation of these data allows three major conclusions: (1) Neotropical regions are not hot spots for myxomycete biodiversity on earth, (2) myxomycetes occur in the Neotropics in lower abundance than in temperate or semiarid zones, and (3) Neotropical myxomy- cetes invade unusual microhabitats, whereas other micro- habitats well-known from temperate zones are sometimes very poor. Examples are inflorescences of Neotropical Zingiberales and epiphyllic liverworts on living leaves. (Supported by the National Science Foundation)