According to records available in the literature, 380 species of fungi and fungus-like organisms are known for the state of Quintana Roo on the Yucatán Peninsula of Mexico. We carried out mycological surveys in this state, following the classical methods for collecting, describing, and curating macrofungi. As a result of our research, 21 species are recorded for the first time for Quintana Roo, and Amanita arenicola O. K. Milller & Lodge, Inocybe xerophytica Pegler, and Russula cremeolilacina Pegler are recorded for the first time for Mexico. The distinctive characteristics and photographs are provided for the new records. As a result of this study, 401 species of macrofungi are known for Quintana Roo.

Alsophila firma is a tree fern that is distributed mainly in tropical montane cloud forest (TMCF) and is considered as a threatened species. Arbuscular mycorrrhizal fungi (AMF) have been proposed as an alternative in rescue programs of endangered species. However, our knowledge about diversity of AMF and mycorrhizal status of the species of TMCF is limited. In Mexico TMCF shows different degrees of conservation because of fragmentation and land use change. In this study, we evaluated the level of colonization, richness and abundances of spores of AMF in three fragments with different conservation status: conserved (100 years), secondary vegetation (17 years) and disturbed. For this, soil samples and roots were collected from five individuals of A. firma per site, with at least 100m away from each other; a total of 100cm of roots were analysed per site. Root samples showed AMF and occasionally dark septate fungi (DSF) colonizations. For the overall study, 19 species of AMF were recorded: Gigaspora (7), Acaulospora (4), Glomus (4), Funneliformis (2), Sclerocystis (1) and Scutellospora (1). The dominant species in the three sites were Funneliformis geosporum and Acaulospora scrobiculata. The highest diversity (H’) and evenness (J’) (p<0.05) were found in the conserved site (H’=1.7, J’=0.66), when compared to the secondary vegetation (H’=1.5, J’=0.61), and the disturbed site (H’=0.74, J’=0.41). Statistical analysis showed that the AMF degree of colonization was significantly higher (p<0.05) in the conserved site; although, the disturbed site showed low richness and abundances of AMF, the degree of root colonization did not differ statistically (p90%. The present study confirmed that A. firma is a mycorrhizal species that exhibits high levels of colonization even in disturbed sites. We suggest that F. geosporum and A. scrobiculata may have the potential to inoculate the gametophyte and young sporophyte of A. firma, to support restoration programs, because of their abundances and high tolerance to disturbed sites.

Background and Aims: The genus Melanogaster is characterized by its hypogeous to semi hypogeous habit, brownish basidiomata, gel-filled gleba locules, and globose to ellipsoid basidiospores. The genus is distributed in temperate zones, but sequences from Coccoloba root tips and a few basidiome collections have revealed its presence in the tropics. The aim of this article is to describe a new species of Melanogaster based on ecological, molecular, and morphological data. Methods: Specimens were collected in urban vegetation of Quintana Roo in the Yucatán Peninsula, Mexico. For morphological description, the classic protocols for sequestrate fungi were followed. The dried material was deposited in the mycological herbarium “José Castillo Tovar” of the Instituto Tecnológico de Ciudad Victoria (ITCV) and the herbarium of the Universidad Autónoma de Yucatán (UADY). Key results: Melanogaster coccolobae is presented as a new species from the urban gardens of Quintana Roo based on ecological, molecular, and morphological evidence. This species is characterized by its hypogeous to semi hypogeous basidioma, greyish orange, brown to reddish brown peridium composed of two layers, sweet smell, subglobose, ellipsoid or piriform basidiospores, and by its mycorrhizal association with Coccoloba spicata. Conclusions: Melanogaster coccolobae is the first species described from the Mexican Caribbean from urban gardens with Coccoloba spicata. More studies about the tropical sequestrate fungi are recommended. Antecedentes y Objetivos: El género Melanogaster se caracteriza por su hábito hipogeo a semi hipogeo, basidiomas parduscos, gleba con lóculos llenos de gel y basidiosporas globosas a elipsoides. El género se distribuye en zonas templadas, pero secuencias de ectomicorrizas de Coccoloba y pocas colecciones de basidiomas han revelado su presencia en los trópicos. El objetivo de este artículo es describir una nueva especie de Melanogaster a partir de datos ecológicos, moleculares y morfológicos. Métodos: Los especímenes fueron recolectados en jardines urbanos de Quintana Roo en la Península de Yucatán, México. Para la descripción morfológica se siguieron los protocolos clásicos para hongos secuestrados. El material se depositó en el herbario micológico “José Castillo Tovar” del Instituto Tecnológico de Ciudad Victoria (ITCV) y en el herbario de la Universidad Autónoma de Yucatán (UADY). Resultados clave: Melanogaster coccolobae se presenta como una nueva especie de los jardines urbanos de Quintana Roo con base en evidencia morfológica, ecológica y molecular. Esta especie se caracteriza por sus basidiomas hipogeos a semi hipogeos, peridio naranja grisáceo, marrón o marrón rojizo, compuesto por dos capas, olor dulce, basidiosporas subglobosas, elipsoides o piriformes y por formar asociación micorrízica con Coccoloba spicata. Conclusiones: Melanogaster coccolobae es la primera especie descrita del Caribe mexicano en jardines urbanos con Coccoloba spicata. Se recomiendan más estudios sobre los hongos secuestrados tropicales.