New species of Elaphomyces (Elaphomycetaceae, Eurotiales, Ascomycota) from tropical rainforests of Cameroon and Guyana

The sequestrate false truffles <I>Elaphomyces favosus</I>, <I>E. iuppitercellus</I>, and <I>E. labyrinthinus</I> spp. nov. are described as new to science from the Dja Biosphere Reserve, Cameroon. <I>Elaphomyces adamizans</I> sp. nov. is described as new from the Pakaraima Mountains of Guyana. The Cameroonian species are the first <I>Elaphomyces</I> taxa to be formally described from Africa, occurring in lowland Guineo-Congolian tropical rainforests dominated by the ectomycorrhizal (ECM) canopy tree <I>Gilbertiodendron dewevrei</I> (<I>Fabaceae</I> subfam. <i>Caesalpinioideae</I>). The Guyanese species is the third to be discovered in lowland tropical South America, occurring in forests dominated by the ECM trees <I>Pakaraimaea dipterocarpacea</I> (<I>Dipterocarpaceae</I>) and <I>Dicymbe jenmanii</I> (<I>Fabaceae</I> subfam. <I>Caesalpinioideae</I>). Macromorphological, micromorphological, habitat, and DNA sequence data are provided for each new species. Molecular and morphological data place these fungi in <I>Elaphomycetaceae</I> (<I>Eurotiales, Ascomycota</I>). Unique morphological features are congruent with molecular delimitation of each of the new species based on a phylogenetic analysis of the rDNA ITS and 28S loci across the <I>Elaphomycetaceae</I>. The phylogenetic analysis also suggests that a common ancestor is shared between some <I>Elaphomyces</I> species from Africa and South America, and that species of the stalked, volvate genus <I>Pseudotulostoma</I> may be nested in <I>Elaphomyces</I>.