Two new species of Lepiota (L. squamulodiffracta and L. sosuensis) and a new record (L. subgranulosa) are described based on collections made in the Dominican Republic. The phylogenetic position of the species based on nrITS data is analyzed and discussed. L. squamulodiffracta belongs in section Lepiota, and it is characterized by the velar patches on pileus split up into numerous minute squamules, striate-sulcate pileus up to the center, and penguin-shaped spores. L. sosuensis has overall white basidiocarps, dextrinoid and metachromatic spores, trichodermial pileus covering, and rare clamp-connections. L. subgranulosa stands out morphologically by the spurred spores with one or several protuberances that give the spores an irregular outline.

A recent collection of Lepiota spiculata from the Dominican Republic is presented here. Macro-and micromorphological features of L. spiculata are described in detail, and its evolutionary (phylogenetic) position within Lepiota sect. Ovisporae, in the subincarnata/brunneoincarnata clade, is assessed on the basis of a combined nrLSU + nrITS + rpb2 + tef1 analysis. Additionally, high levels of deadly amatoxins were detected and quantified in L. spiculata for the first time by HPLC analysis; in particular, α-amanitin was found at concentrations up to approximately 4 mg/g dry weight, which render L. spiculata a potentially lethal mushroom, if ingested.

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Smithiomyces dominicanus is described as new, based on collections made in the Dominican Republic. Morphologically this taxon is very similar to S. mexicanus, but differs in the non-umbonate pileus, the broad stipe base and the smooth basidiospores as seen under light microscope, but with isolated, small warts under SEM. Molecular (nrITS) data also supports the recognition of this taxon as a separate species.