Lactarius agglutinatus can be recognized by its macroscopic characters and its ecology (mycoquebec.org), but is part of a group of Lactarius difficult to distinct from each other. Lactarius agglutinatus has been reported from only 7-8 sites since its description by Burlingham (1908). Hesler and Smith, despite extensive study of North American Lactarius (see Hesler and Smith 1979), have never seen a fresh specimen of this species. On the other hand, this Lactarius species is not well known by mycologists. It might be fruiting rarely and remain unseen. Lactarius agglutinatus therefore classifies as Data Deficient (DD).
Lactarius agglutinatus Burl., Memoirs of the Torrey Botanical Club 14 (1): 42 (1908).
There is no known synonym of Lactarius agglutinatus.
Even though the species can be fairly easily recognized by its macroscopic characters and its ecology (mycoquebec.org), Lactarius agglutinatus has been reported from only 7-8 sites since its description by Burlingham (1908).
Lactarius agglutinatus has been reported in the United States from North Carolina (Pisgah Mountain; mycoportal.org, Burlingham 1908), Tennessee (Blount Co.; mycoportal.org), Georgia (Rabun Co.; mycoportal.org), Texas (Newton Co., Orange Co.; D. Lewis, personal communication) and New York (Oswego Co.; CNYMS 2015). Lactarius agglutinatus species has also been found in Canada in Quebec province on the island of Montreal (Lamoureux 2008).
There are 7-8 localities where Lactarius agglutinatus is known to grow. The species has been last seen in 2015 (CNYMS 2015 and D. Lewis, personal communication), but more information on this species distribution and abundance would be necessary to evaluate a population trend or a total number of mature individuals.
USA: 1 site in NC (1907,1908), 1 in TN (1962,1968), 1 in GA (1955), 1 in NY (2015), 1 in USA unknown location (1996), 2 in TX (2004//2015). See mycoportal.org, mushroomobserver.org, CMYM 2015, Hesler and Smith 1979 and GBIF 2014. Also D. Lewis, personal communication.
Canada: 1 site in Quebec province (1997 twice). See Lamoureux 1998.
Lactarius agglutinatus has distinctive macroscopic features, but is part of a difficult Lactarius group. Yet, Lactarius are popular mushrooms and we consider that they are picked when found. It is expected that Lactarius agglutinatus is rarely overlooked, but that it is often misidentified when collected.
Population Trend: Uncertain
Lactarius agglutinatus is a mycorrhizal fungus species so it is dependent on living host trees for population viability. This mutually beneficial symbiotic association between fungus and plant host roots conveys numerous critical advantages for plant host survival. Mycorrhizal fungi are essentially the uptake organs for many nutrients i.e., nitrogen, phosphorus, numerous micronutrients, i.e., boron, selenium, copper, and plays a major role in uptake of water. Both the fungus and the plant host does not exist in nature without each other.
Lactarius agglutinatus grows from July to September, solitary or scattered on the ground under hardwoods and mixed woods, usually with oaks (Bessette 1997). The original description (Burlingham 1908) mentions that the species grows in rather sandy soil in oak-chestnut woods and frequently under flowering dogwood. In Quebec province (Canada), it was found on sandy soil in a very old forest of mixed Carya ovata, Quercus rubra and Tilia americana. The common host tree between these observations is oak (Quercus).
There is no major threat currently known to affect Lactarius agglutinatus habitat.
At least 5 out of the 7-8 sites where Lactarius agglutinatus has been seen are located in parks with a certain level of biodiversity protection (national parks, state forest, private reserve). No other conservation action is currently taken to protect L. agglutinatus.
Within-range hardwood forests containing oak should be inventoried to better define Lactarius agglutinatus population distribution, size and trends. Even though many L. agglutinatus sites are already located in protected areas, their actual level of protection should be evaluated.
Lactarius agglutinatus is part of a group of Lactarius difficult to differentiate from each others. The taxonomy of Lactarius agglutinatus should be clarified through genetic sequencing.
Bessette, A. E., Bessette, A. R., Fischer, D. W. (1997). Mushrooms of Northeastern North America. Syracuse University Press, 551 p.
Burlingham, G.S. 1908. A Study of the Lactariae of the United States. Mem. Torrey Bot. Club 14: 1-109.
Central New York Mycological Society. (2015). September recap. In The Fungal Gazette, October 2015.
Hesler, L. R. & Smith, A. H. (1979). North american species of Lactarius. The University of Michigan Press, 841 p.
Lactarius agglutinatus. (2014). Retrieved 20 April 2016 from gbif.org
Lactarius agglutinatus Burl. Retrieved 20 April 2016 from mycoportal.org
Lactarius agglutinatus. (2014). Retrieved 20 April 2016 from mycoquebec.org.
Lamoureux, Y. (2008). Lactarius agglutinatus Burl. (A) / Lactaire agglutiné. Retrieved 20 April 2016 from flickr.com