Lactarius haugiae is a species only known to develop in small relicts of subtropical cloud forests distributed in Xalapa city, Veracruz state (eastern Mexico) extremely reduced due to urban development. These forests are extremely influenced by urban activities and comprise small and isolated patches, so the habitat of L. haugiae is extremely compromised by the threats of its unique habitat. Even while the whole area has been extensively studied for 50 years by G. Guzmán, L. Montoya and V. Bandala and other researchers from the “Instituto de Ecología A.C.” it has been found only one subpopulation with two sites and 13 observations.
Even while the known distrubution of L. haugiae is based on few observations, it is robust since we have tested the DNA barcode of the type specimen against a soil fungi database from Mexico. Doing so we discarded the association of L. haugiae with other Fagaceae (Quercus spp) and confirmed its restricted geographic distribution.
Lactarius haugiae should be listed as Vulnerable (VU) under criterion C2a(i) as the number of estimated localities is not more than 50 and population estimate below 100 mature individuals in each subpopulation; with ongoing and projected habitat loss due to change in land use of 30% in the last 15 years and 30% in the next 15 years.
Despite 50 years of extensive study there is only one know subpopulation. The forests where L. haugiae develops are isolated, fragmented, and extremely influenced by human activities. All the surrounding areas of these forests have been changed entirely to urban territories and L. haugiae population is declining due to deforestation, pollution, and edge effects.
Lactarius haugiae has a convex pileus with the center depressed to infundibuliform when mature, viscid, zonate, with yellowish colors. The orange tinges are more evident at pileus center, staining brown when handled. Lamellae adnate to subdecurrent, ventricose, yellowish-cream to yellow-orange colored. The latex is white, not staining white paper and very hot. Lactarius haugiae is similar to several Lactarius species like L. yazooensis, L. olympianus, L. psammicola f. glaber, L. subvillosus and L. acerrimus, but differs by pileus shape, surface, and colors, lamellae arrangement and latex appearance, color, and taste (Bandala et al., 2016).
Lactarius haugiae is only known to develop in forests distributed in Xalapa city, Veracruz state (eastern Mexico). Besides this subpopulation, there has been reported from nowhere else. This species grows in small relicts of subtropical cloud forests with Quercus spp. and Carpinus caroliniana trees. These areas have been intensively studied at least for 50 years. Even when these sites are protected, edge effects and pollution via atmospheric deposits due to the human activities of Xalapa city indeed affects L. haugiae and its hosts. This species should be protected because of its scarce distribution into urban forests immersed in highly disrupted areas, and the pressures of its habitat.
The records of L. haugiae are limited to the center of Veracruz state in Southeast Mexico. Its known distribution is limited to the “Santuario Bosque de Niebla” and the forest area that surrounds the botanical garden of the “Instituto de Ecología A.C.” (Bandala et al., 2016) in Xalapa city. The forests surrounding Xalapa city have been intensively studied by different mycologist during the past 50 years at least, by Guzmán, Bandala, Montoya, etc from the “Instituto de Ecología A.C.” who have been describing new Lactarius species from these areas. Despite this, this speceis has been found only in two sites with 13 observations.
The whole known population of L. haugiae is limited to the center of Veracruz state exclusively in southeast Mexico. There is only one subpopulation divided in two forest fragments: “Santuario Bosque de Niebla”, a space under protection by the “Instituto de Ecología A.C.” where there has been harvested 10 times; and the forest area that surrounds the botanical garden of the “Instituto de Ecología A.C.”, also in the Xalapa city, where there has been harvested three more times (Bandala et al., 2016). Both localities represent a fragmented single subpopulation developing in small patches of vegetation immersed in Xalapa city, under extremely anthropogenic pressures due to the urban surrounding lands.
The known distribution of the species is robust since we have tested the DNA barcode of the type specimen against a soil fungi database from Mexico (unpublished data). Thanks to this, we discarded the association of L. haugiae with other Fagaceae forests (Quercus spp) and also we confirmed that it has not a wider distribution.
Population Trend: Decreasing
Lactarius haugiae is gregarious. It has been collected in cloud forests with Quercus spp. and Carpinus caroliniana trees (Bandala et al., 2016). For other species of Lactarius from Veracruz like L. acatlanensis, it has been demonstrated the association with species of Fagaceae like Fagus grandifolia var. mexicana (Montoya et al., 2017), which distributes close to the sampling areas of L. haugiae. Testing against a soil fungi database from Mexico (unpublished data) we have discarded the distribution of L. haugiae in other Fagaceae forests of Mexico (Quercus spp). Veracruz, particularly the area surronding Xalapa city have been under intense scrutiny by different researchers during the past 50 years at least; so L. haugiae has a very specific distribution associated to some mountain cloud forest ectomycorrhizal host, probably F. grandifolia var. mexicana.
The subtropical cloud forest, particularly those in Veracruz state are highly threatened due to changes in land uses to convert forests areas into urban territories (Williams-Linera et al., 2015). All the land that surrounds the “Santuario Bosque de Niebla” has been dramatically changed to cattle lands, increasing the isolation of different relicts of this vegetation type across Veracruz state. Also, the areas around the “Instituto de Ecologia A.C.” are urban territories where threats like edge effects and pollution via atmospheric deposits, affect L. haugiae and its hosts.
Currently the “Instituto de Ecología A.C.” protects the “Santuario Bosque de Niebla” where L. haugiae the only subpopulation is known to develop. This site represents one of the last relicts of subtropical cloud forest around Xalapa, in Central Veracruz (Bandala et al., 2016).
One of the main needs is to increase the sampling effort in other forest patches proximate to the “Santuario Bosque de Niebla” and the “Instituto de Ecología A.C.”. Doing this would help to elucidate if Lactarius haugiae known distribution is constrained by the absence of records, or if it represents the natural species distribution range. At the same time, this would allow establishing biological corridors between adjacent areas where L. haugiae develop and ensure genetic exchange. Also, is necessary to elucidate who is the main ectomycorrhizal host of L. haugiae in those sites, to ensure the protection of both species. It will be needed also to investigate for possible edge effects in populations of Lactarius haugiae due to the limited distribution of this species.
There are not reports about edibility or use of this species.
Bandala, V. M., Montoya, L., & Ramos, A. (2016). Two new Lactarius species from a subtropical cloud forest in eastern Mexico. Mycologia, 108(5), 967-980.
Montoya, L., Bandala, V. M., Ramos, A., & Garay-Serrano, E. (2017). The ectomycorrhizae of Lactarius rimosellus and Lactarius acatlanensis with the endangered Fagus grandifolia var. mexicana. Symbiosis, 73(2), 135-144.
Williams-Linera, G., López-Barrera, F., & Bonilla-Moheno, M. (2015). Estableciendo la línea de base para la restauración del bosque de niebla en un paisaje periurbano. Madera y bosques, 21(2), 89-101.