Collared Earthstar / Spring / Summer / Autumn / Inedible

The Collared Earthstar (Geastrum triplex) is a truly unique fungus that looks like it’s stepped straight out of a fairy tale. Found in woodlands across the UK, this fascinating mushroom starts as a simple puffball before splitting open into star-like rays with a central spore sac. Its striking, otherworldly appearance makes it a favourite among fungi enthusiasts and nature lovers alike.

In this post, we’ll guide you through how to identify the Collared Earthstar, where to spot it, and why this mushroom is such a special discovery for anyone exploring the natural world.

Scientific Name

Geastrum triplex 

Common Names

Collared Earthstar, The saucered earthstar, The triple earthstar

Family

Geastraceae

Habitat

Collared Earthstars are a saprobic species, deriving nutrients from decomposing organic matter. The fruit bodies are usually found growing singly or more commonly in groups in hardwood forests where much humus has accumulated.

Description

A fairly common fungus in Autumn, often appearing in  the same area every year. 

Identifying Features of Collared Earthstar: 

Immature fruit bodies are spherical, resembling puffballs but with pointed beaks As the fungus matures, the outer layer of tissue (the exoperidium) splits into four to eight pointed segments that spread outwards and downwards, lifting and exposing the spherical inner spore sac. The spore sac when young is white and firm, but ages to become brown and powdery. Often, a layer of the exoperidium splits around the edge of the spore sac so that it appears to rest in a collar or saucer, hence their common name. 

On top of the spore sac is a small pointed beak, (the peristome) which has a small hole. Spores are released from the hole as breezes blow across it, and much larger puffs of spores escape when raindrops hit and compress the spore-sac.

Collared Earthstars are generally larger than other Earthstar species, the diameter of the spore producing sack can be up to 5cm and the ‘arms’  can be twice that size when fully outstretched.

Smell:

No distinctive smell.

Spores:

Brown

Uses

In food

Not real uses in food, while non toxic they are tough and leathery

Medicinal Uses of Collared Earthstar

Earthstars were used medicinally by the indigenous peoples of the Americas. The Blackfoot called them ka-ka-toos, meaning “fallen stars”, and according to legend, they were an indication of supernatural events. 

In traditional Chinese medicine, G. triplex is used to reduce inflammation in the respiratory tract, and to stanch bleeding and reduce swelling.

But there is little evidence to suggest they are effective.

Known hazards

No known hazards.

Potential lookalikes

They are quite distinctive when mature but In its ‘egg’ stage the Collared Earthstar is very difficult to identify; it looks quite similar to many other members of the gasteromycetes group of fungi, though they tend to be smaller than the Collared Earthstar. Think Stink Horn.

References:

https://www.first-nature.com/fungi/geastrum-triplex.php

https://www.discoverwildlife.com/how-to/identify-wildlife/how-to-identify-earthstars