Common names: barometer earthstar, Hygroscopic Earthstar.
Extract from Wikipedia article: Astraeus hygrometricus, commonly known as the hygroscopic earthstar, the barometer earthstar, or the false earthstar, is a species of fungus in the family Diplocystaceae. Young specimens resemble a puffball when unopened. In maturity, the mushroom displays the characteristic earthstar shape that is a result of the outer layer of fruit body tissue splitting open in a star-like manner. The false earthstar is an ectomycorrhizal species that grows in association with various trees, especially in sandy soils. A. hygrometricus was previously thought to have a cosmopolitan distribution, though it is now thought to be restricted to Southern Europe, and Astraeus are common in temperate and tropical regions. Its common names refer to the fact that it is hygroscopic (water-absorbing), and can open up its rays to expose the spore sac in response to increased humidity, and close them up again in drier conditions. The rays have an irregularly cracked surface, while the spore case is pale brown and smooth with an irregular slit or tear at the top. The gleba is white initially, but turns brown and powdery when the spores mature. The spores are reddish-brown, roughly spherical with minute warts, measuring 7.5–11 micrometers in diameter.
Hygroscopic earthstar mushrooms (Astraeus hygrometricus) on a lawn on Gilchrist Avenue. College Station, Texas, November 17, 2017 293, Gilchrist Avenue, College Station, Brazos County, Texas, 77840, United States
Hygroscopic earthstar mushrooms (Astraeus hygrometricus) on a field near oaks in Washington-on-the-Brazos State Historic Site. Washington, Texas, February 27, 2019 23200 Park Rd, Washington, TX 77880, USA
Hygroscopic earthstar mushrooms (Astraeus hygrometricus) on a lawn near Robinson Ferry Road in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 28, 2019 23400 Park Rd 12, Washington, TX 77880, USA
Mature opened hygroscopic earthstar mushrooms (Astraeus hygrometricus) on a lawn near Robinson Ferry Road in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 28, 2019 23400 Park Rd 12, Washington, TX 77880, USA
Group of mature hygroscopic earthstar mushrooms (Astraeus hygrometricus) on a lawn near Robinson Ferry Road in Washington-on-the-Brazos State Historic Site. Washington, Texas, December 28, 2019 23400 Park Rd 12, Washington, TX 77880, USA
Barometer earthstar mushroom (Astraeus hygrometricus) on a lawn in Washington-on-the-Brazos State Historic Site. Washington, Texas, January 24, 2021 23400 Park Rd 12, Washington, TX 77880, USA
Barometer earthstar mushroom (Astraeus hygrometricus)(?) on Forest Road 203 on Richards Loop Trail in Sam Houston National Forest. Texas, August 28, 2021 Forest Rd 203, Montgomery, TX 77356, USA
Mature barometer earthstar mushrooms (Astraeus hygrometricus) in Bastrop State Park. Bastrop, Texas, April 15, 2023 Lost Pines Trail, Bastrop County, Texas, 78602, United States
Dried barometer earthstar mushrooms (Astraeus hygrometricus) in Bastrop State Park. Bastrop, Texas, April 15, 2023 Lost Pines Trail, Bastrop County, Texas, 78602, United States
Last year barometer earthstar mushrooms (Astraeus hygrometricus) in Bastrop State Park. Bastrop, Texas, April 15, 2023 Lost Pines Trail, Bastrop County, Texas, 78602, United States
Spores (in KOH) of dry earthstar mushrooms Astraeus hygrometricus collected in Bastrop State Park. Bastrop, Texas, April 15, 2023
Barometer earthstar mushrooms (Astraeus hygrometricus) in open grassy area in Washington-on-the-Brazos State Historic Site. Washington, Texas, November 26, 2023 Washington-on-the-Brazos State Historic Site, 23400, Park Road 12, Washington, Washington County, Texas, 77880, United States
Barometer earthstar mushrooms (Astraeus hygrometricus) in prairie in Washington-on-the-Brazos State Historic Site. Washington, Texas, November 26, 2023 Washington-on-the-Brazos State Historic Site, 23400, Park Road 12, Washington, Washington County, Texas, 77880, United States
Spores (in Melzer) of barometer earthstar mushrooms (Astraeus hygrometricus) collected in Washington-on-the-Brazos State Historic Site. Washington, Texas, November 26, 2023