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Calostoma insigne (Berk.) Massee

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Scientific name
Calostoma insigne
(Berk.) Massee
Common names
IUCN Specialist Group
Mushroom, Bracket and Puffball
Assessment status
Assessment date
IUCN Red List Category
IUCN Red List Criteria
Ngadin, A.A.
Mueller, G.M.

Assessment Notes

The content on this page is fetched from The IUCN Red List of Threatened Species: https://www.iucnredlist.org/species/125434353/125435555


Based on the extremely high rates of habitat loss (30% from 2005 to 2015; 21% projected from 2019-2050 - Estoque et al. 2019) it is suspected that this species is undergoing a population decline exceeding 50% within three generations (50 years). It therefore qualifies as Endangered A4c.

Geographic range

Calostoma insigne is found in Thailand, Malaysia, Indonesia and Papua New Guinea. The species has a fragmented distribution in Southeast Asia and it has been described from three localities of Indonesia, in Borneo, Java and Sumatra. It has been reported to be found in Australia but it is unlikely that this is the same species and for now it is excluded from this assessment (Döring 2015).

Population and Trends

The species is ectomycorrhizal, forming symbiotic associations with Dipterocapceae trees in South East Asia. It has a fragmented distribution in Southeast Asia (Döring 2015) and has been reported from Indonesia (Borneo, Java, Sumatra, New Guinea), Malaysia, Thailand, Papua New Guinea and the Philippines.

It was collected in Peninsular Malaysia at Frazier’s Hill and other records were collected in Sarawak at Gunung Gading National Park (Malaysia). In Thailand, this species has been widely collected in Sisaket province or forest areas in the northeast. 

There is limited direct data to calculate the population trend, but old growth forest in Malaysia, Indonesia and Papua New Guinea have seriously declined due to deforestation for agricultural activity including oil palm plantations. There was a 30% loss of forest in southeast Asia from 2005-2015 (Estoque et al. 2019), and this is likely to continue - with projected forest cover loss in the region estimated at 21% from 2019 to 2050 (Estoque et al. 2019). Over the 50 year period (3 generations of this species) from 2000 to 2050, forest loss is therefore expected to exceed 50%, and this is precautionarily suspected to also result in a population decline of this species exceeding 50% within the same timeframe.

Population Trend: decreasing

Habitat and Ecology

The species is ectomycorrhizal, generally forming symbiotic associations with Dipterocarpaceae trees. Calostoma from Malaysia has been associated with Castanopsis species (H. Besl pers com). It typically begins development underground, and has been found in regions of humid tropical rainforest of southeast Asia. Usually this species is found growing along hills with the soil and decayed leaves during rainy season. The species was shown to form ectomycorrhizae by using isotopic labelling, molecular and morphological analyses (Döring 2015).


There are high rates of forest loss for agricultural activities including palm oil production across a range of countries especially in Malaysia, Indonesia and Papau New Guinea, in southeast Asia.

Industrial cultivation of oil palm trees has led to the deforestation and degradation of humid rainforest habitat and reduced the population of Calostoma insigne associated with tree species from the family Dipterocarpaceae. In southeast Asia, Dipterocarpaceae species dominate the forest canopy and are abundant in neotropical forests (Corlett and Primack 2011).

Calostoma insigne is undergoing decline due to habitat loss, with conversion of natural rainforest to palm oil areas where this specialist fungus is unable to survive.

Conservation Actions

Use of Landsat TM imagery to observe any changes in land use and oil palm will be beneficial to monitor the situation of this species' habitat. With growing political concern regarding the situation of old growth forests in southeast Asia, some areas are becoming reserved as national parks or other forest reserves.

Use and Trade

This is an edible species, which is collected particularly in northern Thailand and in Borneo, but this is small scale collection for local consumption.

Source and Citation

Ngadin, A.A. 2019. Calostoma insigne. The IUCN Red List of Threatened Species 2019: e.T125434353A125435555. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T125434353A125435555.en .Accessed on 1 February 2024

Country occurrence