This emblematic ectomycorrhizal species strictly associates with Nothofagus hosts in Patagonian forests (Chile and Argentina).
The distribution of Amanita merxmuelleri is scattered on the western and southern side of the Andes, along the whole distribution range of Nothofagus. In Chile, it was collected from the region VII (Maule) to XV (Magallanes), while in Argentina it only occurs in Tierra del Fuego.
Although populations are scattered and usually not abundantly fruiting, Amanita merxmuelleri is found over a very broad area in Patagonia, with the capacity to associate with multiple Nothofagus species.
Population Trend: Stable
This ectomycorrhizal species associates exclusively with Nothofagus species in Patagonia. It was found with multiple Nothofagus hosts, such as N. dombeyi, N. pumilio and N. obliqua. It has a wide distribution along te Andes from latitudes 35º to 55º. Its only ecological restrictions seem to be linked with sites that are relatively oceanic, since in Argentina it is only found South of the Andes in Tierra del Fuego.
This species is associated with an increasingly threatened Nothofagus forest. Deforestation, particularly in the Northern range of its distribution, and forest fires (intentional and accidental due to drought and climate change) are a growing threat.
In Chile, several known populations lies within protected areas at the regional or national level (Karukinka Reserve, Magallanes Nacional Reserve, Puyehue National Park, Los Ruiles Nacional Reserve, Nahuelbuta National Park, Rucamanque Reserve).
Further research is needed to understand the biology of the species (fruiting patterns) as well as its ecology (habitat requirement, host specificity and interactions). Although the species has a wide distribution with multiple Nothofagus hosts, its population trends are currently unknown.
In Chile, the species is collected and locally consumed by mapuche and rural communities in the BioBio region to the South (Salazar Vidal 2016).
Comité clasificacíon de especies silvestres (2014) Ministerio de Medioambiente, Gobierno de Chile. http://www.mma.gob.cl/clasificacionespecies/ficha11proceso/FichasPAC_11RCE/Amanita_merxmuelleri_11RCE_02_PAC.pdf
Garrido N, Bresinsky A (1985) Amanita merxmuelleri (Agaricales), eine neue Art aus Nothofagus-Wäldern Chiles. Bot. Jahrb. Syst. 107: 521-540.
Garrido N (1988) Agaricales s.l. und ihre Mykorrizen in den Nothofagus-Wäldern Mittelchiles. Bibliotheca Mycologica 120, J. Cramer, Berlin,
Stuttgart. ISBN 3-443-59021-7.
Salazar Vidal VE (2016) Amanita diemii Singer y Amanita merxmellueri Bresinsky & Garrido (Agaricales, Basidiomycota), las amanitas comestibles de Chile. Bol. Micol. 31: 28–35.
Truong C, Sánchez-Ramírez S, Kuhar F, Kaplan Z, Smith ME (2017) The Gondwanan connection – Southern temperate Amanita lineages and the description of the first sequestrate species from the Americas. Fungal Biology 121: 638–651. https://doi.org/https://doi.org/10.1016/j.funbio.2017.04.006
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