We studied species of Leucoagaricus and Leucocoprinus collected in the Dominican Republic over the past 10 years using morphological and molecular methods and carefully compared our collections with previously described neotropical taxa. Twelve new species, eight in Leucoagaricus (La. bulbiger, La. caeruleovertens, La. margaritifer, La. pegleri, La. roseovertens, La. silvestris, La. stillatus, La. turgipes) and four in Leucocoprinus (Lc. antillarum, Lc. fuligineopunctatus, Lc. microlepis, Lc. scissus) are described. Additional records of previously described taxa are also discussed, including the first molecularly annotated occurrences of Lepiota guatopoensis, Lepiota mucrocystis, and La. rubroconfusus in their putative natural habitats and of Lc. cretaceus in the neotropics. Lepiota guatopoensis and Lepiota mucrocystis are transferred here to Leucoagaricus based on their phylogenetic placement and morphological characteristics. Color photographs of fresh basidiocarps and line drawings of microscopic characters are provided for all species.
Keywords: 14 new taxa; Agaricaceae; Agaricales; Basidiomycota; ITS; biodiversity; neotropics.