From family Astraeaceae and known to form ectomycorrhizal association with forest trees such as dipterocarp (Dell et al. 2005), Castanae, Eucalyptrus and Alnus.
Synonyms
Astraeus stellatus (Scop.) E. Fisch, Geastrum hygrometricum Pers. [as ‘Geaster‘], Geastrum stellatus (Scop.) Wettst. [as ‘Geaster‘], Geastrum vulgaris Corda [as ‘Geaster‘], Lycoperdon stellatus Scop.

Common name:
Barometer Earthstar, Hygroscopic Earthstar, Water measurer, hed torp, hed phor (Thai & Laos)

This fungus is an ectomycorrhizal fungus and found to form mutualistic symbiosis with Chir Pine (Pinus roxburghii) and sal (Shorea robusta) Chakraborty et al. (2004). It is an edible fungus known as “Kall-Anabe” (stone-mushroom) (Karun and Sindhar, 2014; Pavintra et al., 2015) and it is uniquely consumed in Thailand, Laos and India. It is believed to be used as herbal medicine in China and India (Mallick 2010).
This fungus is harvested when their fruiting bodies are young and sold at high price (USD1-2) to the wholesaler and marked up to USD3-5 by the market sellers to the consumer, and the price can reach up to USD10 – 30 (Dell et al. 2005; Butkrachang et al. 2007). The nature of this fungus is an ectomycorrhizal fungus with Dipterocarp species, make it no method to cultivate this fungus for commercial production.

Has been previously reported from Thailand, Laos, India, China

Unknown.
Population Trend: Uncertain

The fruiting bodies of Astrateus fungus is usually half hidden in the soil and make it difficult to spot them on the ground especially in the area with forest litters (Mortimer et al., 2012). It prefers sandy or lateritic soil in dry lowland dipterocarp forest. It is known to fruit between May to August, which is the rainy season.

Over harvesting and habitat loss/deforestation of dipterocarps has cause this species to decline (Koune 2001).

Astrateus is an obligate ectomycorrhizal fungus, in which its yield is strongly depends on the host plant; e.g Dipterocarps. As such, conservation of dipterocarp forests is the most sustainable manner to indirectly conversing and help to increase the wild production of this fungus.

Surveys and inventories are needed to be conducted to determine the occurrence and distribution of this fungus.

It is an edible fungus (Karun and Sindhar, 2014; Pavintra et al., 2015) that reported to be used as herbal medicine in China and India (Mallick 2010).

Butkrachang S, Boonchieng E, Sardsud U, Sukchotiratana M, Plikomol A, Chairote G, Narongchai P (2007) Wild mushroom database of Chiang Mai community forest. Asian J Biol 3:65–70

Chakraborty I, Mondal S, Pramanik M, Rout D, Islam SS. Structural investigation of a water-soluble glucan from an edible mushroom, Astraeus hygrometricus. Carbohydr Res. 2004 339(13):2249-54.

Dell B, Sanmee R, Lumyong P, Lumyong S (2005) Ectomycorrhizal fungi in dry and wet dipterocarp forests in northern Thailand—diversity and use as food. Proceedings of the 8th Round Table Conference on Dipterocarps, Ho Chi Minh City

Karun, N.C. and Sridhar, K.R. 2014. A preliminary study on macrofungal diversity in an arboretum and three plantations of the southwest coast of India. Current Research in Environmental & Applied Mycology 4:173-187
Koune J (2001) Threatened Mushrooms in Europe. Nature and Environment No. 122. Council of Europe Publishing, Strasbourg Cedex. ISBN 92-871-4666-7

Mallick SK, Swatilekha M, Bhutia SK, Maiti TK (2010) Immunostimulatory properties of a polysaccharide isolated from Astraeus hygrometricus. J Med Food 13(3):665–72
Mortimer, Peter E., Samantha C. Karunarathna, Qiaohong Li, Heng Gui, Xueqing Yang, Xuefei Yang, Jun He et al. “Prized edible Asian mushrooms: ecology, conservation and sustainability.” Fungal Diversity 56, no. 1 (2012): 31-47.

Pavithra, M.,Greeshma,A.A.,Karun,N.C. and Sridhar,K.R.2015. Observations on the spp. of Southwestern India. Mycosphere. 6: 421-432.