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  • Under Assessment
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Amanita westii (Murrill) Murrill

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Scientific name
Amanita westii
(Murrill) Murrill
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Proposed by
David Lewis
David Lewis
Gregory Mueller
Anders Dahlberg

Assessment Notes

Taxonomic notes

Described by W. A. Murrill as Venenarius westii then transferred to Amanita in the same paper. Amanita westii, in section Lepidella,  is characterized by a medium-sized fruiting body that bruises reddish and has chocolate-colored gills. It is an easily identified species due to its reddish stains and medium size. It may be confused with Amanita rubescens, however that species has whitish gills (Murrill 1945). Tulloss and Lewis (1994) have published a modern description with a detailed microscopic data.

Why suggested for a Global Red List Assessment?

Amanita westii is a rare ectomycorrhizal fungus that appears to be endemic to the United States gulf coast. It is only recorded from seven sites in Florida, Mississippi and Texas after 80 years of collecting by mycologist and mushroom clubs.

Geographic range

Amanita westii is endemic to the United States gulf coast. The holotype was collected near Newman’s Lake near Gainesville, (Alachua Co.), Florida. A single site is also known from Apalachicola National Forest (Wakulla Co.) south of Tallahassee.  It has been reported in southern Mississippi (Jackson Co. and Perry Co.) and East Texas (Newton and Hardin Co.).

Population and Trends

7 sites x 10 potential sites x 2 ramets x 10 gamets = 1400 mature individuals.

Murrill described Amanita westii in 1945 from a 1938 specimen found in Florida and did not report any other collections. The species was not seen again until discovered by Lewis in East Texas in 1987.  The Gulf States Mycological Society annual summer and winter forays starting from 1979 and continuing today (2015) found two single collections in Jackson Co.  (1981) and Perry Co., (1991) Mississippi and a single fruiting body (1994) in Wakulla Co., Florida.  The largest collection, composed of five fruiting bodies, was found by Buyck in Texas in 2007.  The last collection, a single fruiting body, was made by Lewis in Big Thicket National Preserve in 2008.

Singer did not report it from Florida (1942-1945).  Thiers’s studies on Texas,  Alabama, Mississippi and Florida mushrooms (1950-1963) also did not report it. Cibula, a Mississippi Mycologist (1975-2005) did not find it.  Alan and Arleen Bessette, who have collected in Florida and southern Georgia since 2000, has not seen this species.

Population Trend: Uncertain

Habitat and Ecology

Amanita westii 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.

Murrill reports it under Quercus in a dry hammock (Murill, 1945). The Wakulla Co. site is a mix pine and hardwood forest. In Mississippi, found in a mesic forest of Pinus, Quercus and Fagus.  In Texas associated with a variety of habitats including: Quercus and Carya;  with Quercus stellata in a Xeric sandyland; on a slope forest with Fagus grandifolia and Quercus alba.

Fruit in summer months from June to September.

Temperate Forest


Severe drought and hurricane damage may impact populations due to tree mortality and forest destruction .  The influx of invasive species such as Chinese Tallow (Sapium sebiferum) and Chinese Privet (Ligustrum sinense) has influenced the overall ecology of the region by replacing native hardwoods.  Another problem is the destruction of plants and soil by feral hogs.  In Florida, urban sprawl may influence their population.  Some sites may be converted to pine plantations.

Housing & urban areasTrend Unknown/Unrecorded

Conservation Actions

In Florida, the Newman’s Lake population status is unknown; the other Florida site south of Tallahassee is in Apalachicola National Forest.  The Mississippi site is within DeSoto National Forest.  The first Texas site (1987) is located on a private preserve whose ownership has changed and its fate unknown.  The large collection of five fruiting bodies is located in a cemetery site and should remain unaltered.  The last collection is within Big Thicket National Preserve, a federally protected area administered by the National Park Service.

Site/area protection

Research needed

Tulloss and Lewis have published a modern description with a detailed microscopic data.  Amanita westii is an easily identified species due to its reddish stains and medium size. In the gulf coast of North America, where A. westii 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. westii so they can target this species during forays. Data from amateur mycologists can be critical to define A. westii population size, distribution and trends, as well as its ectomycorrhizal associations. Annual forays by the Gulf States Mycological Society continues to search for other populations. Lewis continues to monitor one Newton Co. site and areas within Big Thicket National Preserve..

Population size, distribution & trends

Use and Trade


Murrill, W. A.  1944 [1945].  New Florida fungi. 
  Proc. Fla. Acad. Sci. 7:107-127 [1945].

Tulloss, R. E. and D. P. Lewis.  1994.  Amanita westii-taxonomy and distribution.  A rare species from states bordering the Gulf of Mexico. 
Mycotaxon 50: 131-138.

Known distribution - countries

Regional Population and Trends

Country Trend Redlisted