Porphyrellus zaragozae is a rare and conspicuous bolete endemic from northeastern Mexico, particularly from Nuevo León and Tamaulipas where it has been registered in two locations and with fewer than five records since 1982. It grows associated to oak forests, particullarly Q. mexicana and Q. affinis, at 2350-2650 masl. Porphyrellus zaragozae´s habitat is threatened by changes in land use, fires and diseases of their host plants.
This ectomycorrhizal species should be listed as Vulnerable under criteria A3ce given that at least one potential host (Q. mexicana) has a projected reduction of population size by at least 30% in the following 30 years (Gómez-Mendoza and Arriaga 2007) and also because its hosts suffer from fungal pathogens in one of its two known localities.
Porphyrellus zaragozae has a grayish pileus, areolate, profusely reticulated, gray stipe gray; and whitish cream-colored context that becomes green blue when exposed to air. Boletus griseus is a similar species but does stains blue and its context is yellow at the base of the stipe.
Porphyrellus zaragozae is a potentially endemic species from northeastern Mexico, particularly from Nuevo León and Tamaulipas where it has been registered in two locations and with fewer than five records since it was collected in 1982 and described in 1991 (Singer, García and Gómez 1991). It grows associated with forests of Quercus spp. as Q. mexicana and Q. affinis, at 2350-2650 masl. Porphyrellus zaragozae´s habitat is threatened by changes in land use, fires and diseases of their potential host plants. This ectomycorrhizal species should be listed as Vulnerable under criteria A3ce given that at least one potential host (Q. mexicana) has a projected reduction of population size by at least 30% in the following 30 years (Gómez-Mendoza and Arriaga 2007) and also because its hosts suffer from fungal patogens in one of its two known localities.
The only two confirmed locations where Porphyrellus zaragozae has been registered are in the Northeast of Mexico, in the States of Nuevo León and Tamaulipas. There are three more collections deposited in the Field Museum of Natural History (Botany) Fungi Collection, however the identity of these collections is not confirmed and are excluded from this assessment.
There is one record of Porphyrellus zaragozae from Agua del Toro, Municipality of Zaragoza, Nuevo León state in 1982, that corresponds to the type locality. The second record of this species comes from Tamaulipas (1982), in Ejido La Peña-Ejido Aserradero Road, Km. 12, Municipality of Miquihuana, Tamaulipas, where it has been registered in recent years by one of the authors of the species in 2014. Both locations are 35 km away from each other. These localities and some others in Tamaulipas and Nuevo Leon states have been sampled frequently and there are no more records of this species elsewhere. Besides these there are no more records of this species in GBIF database (GBIF Secretariat 2017).
Population Trend: Uncertain
Porphyrellus zaragozae is solitary to gregarious. It grows on the ground, in mixed forests of Quercus spp. (particularly close to Q. affinis and Q. mexicana) and Pinus spp., at an altitude of 2350-2650 masl. Its phenology seems to be restricted to September and October, based on current records.
The main risk factors in the locations where Porphyrellus zaragozae is distributed is land use change due to exploitation of timber resources in local sawmills. Likewise, in recent years there have been forest fires in the areas surrounding the collection sites. There is also a land use change towards livestock and agricultural areas that promote soil compaction and soil enrichment by the addition of organic matter. There is a change of vegetation cover towards shrub species (Rosaceae and Ericaceae). Climate change has been projected to generate a reduction of potential hosts of Porphyrellus zaragozae like Quercus mexicana, whose populations will be reduced by 30% under a conservative scenario by 2050 (Gómez-Mendoza and Arriaga 2007). Furthermore, several Quercus species at sample localities have emergent phytosanitary problems as the rot of heartwood in at least 25% (personal observations) of the populations in the locality of Tamaulipas.
Currently, the localities where this species distributes are not within the polygon of any Natural Protected Area, and it is not registered in any Mexican or international Red List.
To obtain sequences of the type specimen of Porphyrellus zaragozae, or from new specimens collected in the type localities. It is necessary to include them in phylogenetic analyzes to verify if these species are close to others of the same genus or identify other herbarium specimens currently unknown. It is important to identify the Quercus species that are host to P. zaragozae to evaluate the actual potential occupation area of this host species. To explore the possibility of mycorrhization of the oak species of these sites with species such as P. zaragozae, which would require generating strategies to obtain germplasm. To investigate pathogens identity of Quercus at the sampling sites for its potential control.
There are no reports about edibility or use of this species.
Singer R, García J, Gómez LD (1991) Boletinae of Mexico and Central America III. Beih. Nova Hedwigia 102: 69
Porphyrellus zaragozae Singer & J.García in GBIF Secretariat (2017). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2019-05-23.
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: 1545-1555.