- Scientific name
- Amanita morrisii
- Common names
- Morris' Amanita
- Amanite de Morris
- Amanite des pinèdes
- IUCN Specialist Group
- Mushroom, Bracket and Puffball
- Assessment status
- Assessment date
- IUCN Red List Category
- IUCN Red List Criteria
- Langlois, A.
- Dahlberg, A.
is a rare ectomycorrhizal fungus in Northeastern North America. It generally grows on wet soil in association with pines, particularly Pinus rigida
. Even though it is part of a well studied genus, the species, described 1910, has been found in only 14 sites. Its apparent restriction to the Pine Barrens, which are ecosystems that have been loosing and are expected to lose 10% of its area to development within the next 50 years, indicates that A. morrisii
populations will also decline. Its restriction to wetlands within the Pine Barrens makes habitat loss and habitat quality loss critically threatening to A. morrisii
, as water quality and water level is expected to be altered.
In total, less than 10,000 mature individuals are estimated to exist: 14 confirmed sites x50 (times more sites because probably often misidentified and most sites are undiscovered ) x2 functional (genetically unique) individuals per site, five mature individuals per functional individual. Together with ongoing decline, this results in an assessment of Vulnerable (VU) C1.
is only known from North America. In the United States it is reported from Maine (Cumberland Co.), New Jersey (Burlington Co., Ocean Co.), Massachusetts (Barnstable Co., Essex Co., Middlesex Co.), New Hampshire (Carroll Co.; Overholts 1921), maybe New York (Oneida Co.; uncertain identification of specimen) and is expected in neighboring regions (Tulloss, amanitaceae.org). Its presence is also mentioned in Canada from Quebec province (Laurentides, Monteregie; mycoquebec.org).
USA: One site in Maine (1995), four in Massachusetts (1909, 1910, 1911//1927//1995, 2009//2008 twice), six in New Jersey (1983//1983//1988//1995, 1997, 2008, 2011, 2013//2009//2009, 2012) and one in New Hampshire (prior to 1921). Total 12 sites. There is also one uncertain site (specimen has not been thoroughly examined) in New York (2011, 2012). See amanitaceae.org (Tulloss), Overholts 1921, and mushroomobserver.org.
CANADA: Two sites in Quebec province (1997/unknown year). See mycoquebec.org (2015). Also Y. Lamoureux pers. comm.
Population and Trends
Amanita morrisii is known from only 14 sites across northeastern North America. The species is thought to be declining because of habitat loss due to land development. The Nature Conservancy estimates that if the 1990-2000 rate of loss is maintained, about 10% of the Pine Barrens in northeastern North America (i.e., Northeastern Interior Pine Barrens, North Atlantic Coastal Plain Pitch Pine Lowland and North Atlantic Coastal Plain Pitch Pine Barrens) will be lost to urban development within the next 50 years.
Amanita morrisii is fairly easy to identify due to its characteristic dark brown cap that fades slightly with age and its annulus with a colored underside. However, and even though it is part of a popular group (Amanita), A. morrisii is not a well-known species. Thus, we believe A. morrisii is rarely overlooked but often misidentified when found.
There are 14 sites where A. morrisii has been found and we estimate that there are probably up to 50 times more sites. Each site is thought to represent two functional (genetically unique) individuals. Each functional individual is expected to represent five mature individuals. We estimate the total number of mature individuals of A. morrisii to range between 5,000 and 10,000 (cf. Dahlberg and Mueller 2011).
Population Trend: decreasing
Habitat and Ecology
is an ectomycorrhizal fungus species most commonly associating with Pinus rigida
, which is most common in the Pine Barrens of northeastern North America. Thus, the fate of A. morrisii
is linked to the fate of this habitat. Fungus species associated with Pinus rigida
are expected to occasionally associate with other Pinus
species (Horton and Bruns 1998), which would explain why A. morrisii
was found in Quebec where there is P. sylvestris
and P. resinosa
but no P. rigida
fruitbodies are found solitary, in pairs, or gregariously. In Massachusetts, A. morrisii
was found in “black vegetable mold” among mosses of swampy area (Natick collections; Tulloss 1991) or in Chamaecyparis thyoides
swamp (Barnstable Co., Cape Cod, collection). In New Jersey, it was found in wet sand (poor in organic matter) of Pinus rigida-Quercus
barrens, occasionally with Chamaecyparis thyoides
nearby, where soil surface is barely above the level of nearby ponds or lakes (Tulloss, amanitaceae.org). In Chamaecyparis thyoides
swamps, there are typically Pinus rigida
and Betula populifolia
present as well (Laidig and Zampella 1999). In New Hampshire, it was found on the ground in damp woods (Overholts 1921). In Quebec province (Canada), A. morrisii
was found in Sphagnum
under a natural forest of Pinus rigida
and Pinus resinosa
in an open area. The soil was thin and composed of Sphagnum
on bedrock (indicating poor drainage). In Quebec province (Canada), A. morrisii
has also been found with ca. 100 years old Pinus sylvestris
, P. resinosa
and Picea abies
on wet moss over thick hummus and sandy soil in a shaded area (Y. Lamoureux pers. comm.).
The main threat to Amanita morrisii
is habitat loss and reduction in habitat quality, as the Pine Barrens in northeastern North America are being negatively impacted mostly by development of land (Pinelands Preservation Alliance 2016). Amanita morrisii
’s restriction to wetlands within the Pine Barrens makes habitat loss and reduction in habitat quality even more threatening, as water quality and water level is expected to be altered in the Pine Barrens (Pinelands Preservation Alliance 2016). Many historic sites where A. morrisii
occurred are in urban areas and are now likely extirpated.
occurs in at least nine protected sites, either in preserves or parks. Other sites where it occurs should be protected as well.
should be searched for within-range similar habitats to evaluate population size, distribution and population trend. Sites where the species have not been found for a long period of time should be inventoried first to confirm the actual number of extant A. morrisii
is a fairly easily identified species due to its cap color and colored partial veil, but it is not well-known by most mycologists. In northeastern North America, where A. morrisii
is found, there are numerous groups of amateur mycologists. Members of these groups can be recruited and instructed where to find and how to identify A. morrisii
so they can target this species during forays. Data from amateur mycologists can be critical to define A. morrisii
population size, distribution and trends.
Source and Citation
Langlois, A. 2017. Amanita morrisii. The IUCN Red List of Threatened Species 2017: e.T95383179A95385364. https://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T95383179A95385364.en
.Downloaded on 31 January 2021