Foliicolous liverworts as a microhabitat for Neotropical Myxomycetes
Leaves covered with epiphyllous liverworts and lichens were sampled at six localities in Ecuador, Costa Rica and Puerto Rico and screened with the moist chamber method for the presence of myxomycetes. Eleven species of myxomycetes were recovered, with Arcyria afroalpina as a new record for the Neotropics. Three species (Arcyria cinerea, Didymium iridis and D. squamulosum) were recorded with a high frequency (between 59 and 66%) in the moist chamber cultures. Evidence is presented that these three species may occur regularly on epiphyll-covered leaf surfaces as populations of myxoamoebae. Unusual small numbers of sporocarps found in the cultures, along with the occurrence of atypically small sporocarps suggest a microhabitat poor in nutrients. Lowland rain forests with a high annual rainfall seem to provide the best conditions for the growth of epiphyllous myxomycetes. With the plasmodial slime moulds, the study presented herein adds a new group of organisms to the community of epiphyllous cryptogams.