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 moi st chamber method for the presence of myxomycetes. Eleven species of myxomy cetes were recovered, with Arcyria afroalpina as a new record for the Neotr opics. Three species (Arcyria cinerea. Didymium iridis and D. squamulosum) were recorded with a high frequency (between 59 and 66%) in the moist chamb er cultures. Evidence is presented that these three species may occur regul arly on epiphyll-covered leaf surfaces as populations of myxoamoebae. Unusu al small numbers of sporocarps found in the cultures, along with the occurr ence of atypically small sporocarps suggest a microhabitat poor in nutrient s. Lowland rain forests with a high annual rainfall seem to provide the bes t 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.