This species was described in 1976, is known only from Mexico, and only has been reported from ten localities, but some of those localities re very near and may represent the same population. Overall can be recognized four collection areas in Jalisco, one in Mexico City and one in Veracruz. Because Veracruz and Jalisco are the most studied states in Mexico, and only those localities have been reported, it is the most likely that those localities are the only known so far. This species may be in vulnerable condition because it grows in tropical montane could (TMC) forest, which is under severe pressure, and even when also grows in Pinus and Pinus-Quercus forest, one of the most extended vegetation types in the country, a) most of the localities are TMC forest and b) it grows in altitudes of 1150 metes or above, and species living in that altitude will be severely affected by climate change.
Considering the number of known localities, and the possibility of existence of other potentially suitable localities, the number of potential individuals can be estimated in almost 10,000. Considering that models for predicting the effects of climate change have estimate a decline of 68% for the vegetation type over the next 60 years, and the decline of the Quercus species that inhabit temperate and cold location in 30-45%, it can be considered that Marasmius guzmanianus fits the vulnerable category because of criteria C1.
This species was described by Singer (1976), since then nobody has propose any change on it nomenclature. So far we do not have any information regarding it phylogenetic relationships.
Marasmius guzmanianus Singer, Fl. Neotrop., Monogr. 17: 218 (1976)
From the protologue
Pileus dried near “Mohawk”(M&P)i e a deep reddishbrown with paler spots aroundthe umbonate center, glabrous and slightly rugose when dried,about 54 mm broad when dried. Lamellae yellowish white when dried,with not discolorous edges, medium broad to rather broad,subdistant,intermixed with lamlellulae, strongly anastomosing-intervenose,narrowly adnexed. Stipe dark brown below,lighter brown at apex when mature and dried,glabrous,hollow, subequal,85 X 5 mm;basal mycelium white. Context white in the pileus, fleshy, relatively thick
NOTE The documentation of this assessment is being revised and edited when finalized when entered to IUCNs Red-List database. This species was described by Singer in 1976, and typified with a specimen collected in 1960 from La Marquesa, public park near Mexico City. Since 1960 this species has been collected sixteen times, fourteen times from montane cloud forest habitat, only from ten localities in three states (Mexico City, Veracruz and Jalisco). Most of the distributional area for this species is located in a vegetation type subject to high pressure, it is only known from less than ten localities. Two of the localities (Veracruz and Mexico City) are public areas, subject to recreational use, and the rest of the localities are mostly in montane cloud forest.
This species in only known from Mexico. It was collected from Jalisco: San Sebastian del Oeste, in 1994, 1995 and 1998; Zapotlán el Grande in 1984, 1996, 1996 and 2000; Autlán de Navarro in 1989, 1993 and 1994; Mazamitla in 1984. Veracruz: Fraccionamiento las Ánimas in 1975. Mexico City: La Marquesa 1960. All the specimens were collected from 1200-2800masl. Vegetation type was montane cloud forest for all the specimens except three, those were collected near the cloud forest locality but in Pinus or Pinus-Quercus forest. One additional specimen is reported from “Chamela Biological Station”, in the coast of Jalisco (10meters), but it is not included in this report because is a very different ecological condition, and the specimen need to be inspected for taxonomical corroboration before using that information.
Marasmius guzmanianus is a species endemic to Mexico, known from less than ten localities and mostly from montane cloud forest. Localities from Jalisco are in the vicinities of Volcan de Colima, and are separated by tens of kilometers. Localities from other states are hundreds of kilometers apart. With the exception of four localities in Jalisco, the rest of the distribution of the species is fragmentary and in a vegetation type subject to pressure.
Population Trend: Uncertain
Marasmius guzmanianus was collected for first time in montane forest probably in a locality with Abies, 2800masl, but the rest of its known distribution has been reported from montane could forest, or Pinus, Pinus-Quercus o a mixture of this vegetations, in altitudes of 1150m or above. It is known from ten localities and those are scattered on three states. The type locality for the species is in a public recreational park.
Main threats for this species are related with the decline tendencies of the vegetation type where the species inhabit. This species is only known from tropical montane cloud forest (TMC) habitats, Abies, Pinus and Pinus-Quercus forest, but always in localities in high altitude. TMC forests are estimated to decline 68% over the next 60 years (Ponce-Reyes et al. 2012). Even when Pinus-Quercus forest is one of the most extended vegetation types in the country (Rzedowski 2006), deforestation trends are very high in Mexico (Rosete-Verges et al. 2014), and because of climate change Quercus species that inhabit temperate and montane locations are estimated to decline by 30-45% over the next 30 years (Gómez-Mendoza and Arriaga 2007). This species is only known from localities in high altitude, and those may be more susceptible to climate change.
Conservation actions for this species are related with the conservation of their habitat, and may include conventional programs for the conservation of the forest, and or management of the forest.
Additional research needed for this species may include additional records for its distribution, as well as a molecular characterization, producing DNA sequences for barcoding markers, and markers for phylogenetic and macroevolutionary research. Also more information is needed regarding ecological need for this species, specially regarding ectomycorrhizal association.
There are no uses or trade associated with this species.
Gómez-Mendoza L, & Arriaga, L. (2007). Modeling the effect of climate change on the distribution of oak and pine species of Mexico. Conservation Biology, 21(6), 1545-1555.
Ponce-Reyes, R., Reynoso-Rosales, V. H., Watson, J. E., VanDerWal, J., Fuller, R. A., Pressey, R. L., & Possingham, H. P. (2012). Vulnerability of cloud forest reserves in Mexico to climate change. Nature Climate Change, 2(6), 448.
Singer, R. (1976). Marasmieae (Basidiomycetes-Tricholomataceae). Flora Neotropica, 17, 1-347.