- Scientific name
- Agaricus pattersoniae
- Common names
- IUCN Specialist Group
- Mushroom, Bracket and Puffball
- Assessment status
- Assessment date
- IUCN Red List Category
- IUCN Red List Criteria
- Vellinga, E.
- Dahlberg, A.
is restricted to mature Cupressus macrocarpa
stands with an undisturbed duff layer in central coastal California. Its habitat is threatened by developments, decline of Cupressus
due to infection with Seiridium cardinale
and increasing drought. Conservation of mature C. macrocarpa
stands and younger stands that will provide the habitat in the future will effect a number of species that are restricted to this habitat, such as Lepiota
species plus other Agaricus
is assessed as Vulnerable (VU) under criterion C2a(i) as the number of known localities is small (less than 50) and the number of mature individuals numbers about 1,000 with each subpopulation having fewer than 500 mature individuals. It also almost fulfill the criteria for A3c for VU as the number of sites is declining and projected to decline by about around 25% in the next 20 years.
Originally described as Agaricus pattersonae
is probably endemic to California as it only is known from the central coastal region in California (USA): Sonoma County southwards into San Luis Obispo County. A few reports are from the eastern part of the USA but these have to be confirmed.
Population and Trends
Agaricus pattersoniae is known from less than 50 sites based on collections (Mycoportal.org) and recent observations (2009-2015; Mushroomobserver.org) in California (USA). The species and its habitat are currently stable, but is prone to future decline of cypress groves. The fungus grows in the original Cupressus macrocarpa stands, and secondary occurrence in planted stands. C. macrocarpa is native to California where it occurs in two main subpopulations, but is widely planted as windbreaks in coastal areas around the world.
Population Trend: stable
Habitat and Ecology
is saprotrophic in duff of mature (over 40 years old) Cupressus macrocarpa
stands and groves with an undisturbed duff layer, fruiting from (November) December through March, after heavy winter storms. The species does not occur under solitary trees or stands with a well-developed herb and grass layer.
is endemic to California, and occurs in two main natural subpopulations; planted groves exist, but are considered non-native and are threatened with replacement by native tree species. C. macrocarpa
is prone to infection by Seiridium cardinale
which damages and kills older and more exposed trees. Habitat destruction is the main threat; for instance the cypresses at the type locality have been removed. Due to the absence of late winter rains in the winters of 2012-2015 the species has not been fruiting in its usual localities. C. macrocarpa
is currently assessed as Vulnerable on the IUCN Red List because of its restricted range and susceptibility to increased risk of fire due to future climate change.
Most of the main stands of Cupressus macrocarpa
are protected, however, the habitat needs to be properly managed, especially to reduce the risk of fires in the future.
Use and Trade
This is edible like most Agaricus
Source and Citation
Vellinga, E. 2015. Agaricus pattersoniae. The IUCN Red List of Threatened Species 2015: e.T75093504A97167420. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T75093504A75094030.en
.Downloaded on 31 January 2021