Following the recent heavy rain, all sorts of interesting fungi have been popping up in bushland and back yards around the south coast and among some of these have been earthstars.
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Earthstars belong to a group of fungi called gasteromycetes that are related to puffballs.
They have a stomach sac filled with dry spores and a skin (peridium) that is made of three layers that allow an earthstar to do something that no other fungus can and that's move.
As the earthstar matures the outer two layers of skin split and uncurl forming a star with four to 12 petals or rays that spread outwards and downwards, lifting and raising the inner spore sac above the surrounding ground.
Sometimes the petals can lift the earthstar high enough to detach its connection to the parent mycelium.
There is a little hole at the top of the spore sac that releases the spore when a drop of rain hits the spore sac and spores puff out.
The rays close when they dry, and the sac lowers and deteriorates.
The fungus is also known as barometer earthstar because it reacts to the level of humidity in the air.
When the air is dry, the points fold up around the puffball to protect it from weather and from various predators.
However when the air is moist, or when it rains, the points open and expose the center with the rays of the earthstar measuring from 1.5 to 7.5 cm.
Earthstars are inedible and have no culinary value.