Astraeus hygrometricus

Astraeus hygrometricus is a species of fungus in the family Diplocystaceae. Commonly known as the barometer earthstar or the hygroscopic earthstar, it is a widespread species, found in many parts of the world. The fungus was first described scientifically in 1809 by Christiaan Hendrik Persoon, a mycologist from the Netherlands.

Taxonomy

The species was first described in 1809 by Christiaan Hendrik Persoon. The generic name Astraeus is derived from the Greek word Astraios, meaning star-like, and hygrometricus is derived from the Greek words hygros meaning wet and metron meaning measure. This refers to the hygroscopic nature of the fungus, which means it can absorb and hold water from the environment.

Description

The fruit bodies of Astraeus hygrometricus are initially spherical, with a diameter of up to 3 cm. As they mature, the outer layer of tissue splits into several star-like rays that peel back to reveal a spore sac. The rays are hygroscopic, meaning they can absorb water from the environment. In dry conditions, the rays curl up around the spore sac, protecting it. In wet conditions, the rays unfold and expose the spore sac to the elements, allowing the spores to be dispersed.

Habitat and distribution

Astraeus hygrometricus is a widespread species, found in many parts of the world. It is commonly found in forests and woodlands, particularly in areas with sandy soil. The fungus is a saprophyte, meaning it obtains its nutrients from decaying organic matter.

Culinary uses

While not generally considered a choice edible species, Astraeus hygrometricus is sometimes used in the cuisine of certain cultures. In Thailand, for example, it is collected and used in a variety of dishes.

See also

• List of Astraeus species
• Mycology