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Collared earthstar with star-shaped rays around a spore sac
Not a food mushroombeginner-friendly group

Collared Earthstar

Geastrum triplex

A puffball whose outer skin splits into star-shaped rays, often with a saucer-like collar under the spore sac.

Photo: Peta McDonald, CC0
Compiled by Mushroom Forage Map field deskExpert review pendingContent checked
Identification warning

Not a food mushroom.

Season
Late summer to autumn
Habitat
Leaf litter in broadleaf and conifer woods
Underside
No gills or pores; spores puff from a pore in the central sac
Spore evidence
Brown spore mass

Where it grows

Tracked records and known growing zone

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Squares: where people recorded it, brighter where more people did
Verified records
1,002
People who recorded it
646
Most records (northern hemisphere)
Aug–Oct
Records span
2006–2026

Research-grade iNaturalist records, snapshot Aug 27, 2026. The growing zone combines areas where different people have repeatedly verified it. Records show where people looked and found it, not current abundance or permission to gather.

Observation season

When field records occur

Choose a hemisphere · All recorded years; not a current forecast.

Choose the hemisphere you want to study. Country detection is approximate and some countries span the equator.

Compare before concluding

Lookalikes to rule out

Barometer earthstar

harmless

Astraeus rays open when wet and close when dry.

Other earthstars

harmless

Several Geastrum differ in the pore and collar.

Puffballs

harmless

Puffballs lack the star-shaped rays.

Identification

The outer layer splits into four to eight pointed rays that fold back like a star. The central spore sac sits in a saucer-like collar formed by the inner layer. A pore at the top releases puffs of brown spores when raindrops hit.

Uses and ecology

Earthstars decompose leaf litter. The collared earthstar is one of the largest and most common.

Memorable fact

Raindrops act as bellows, puffing spores from the sac.

Sources

Never eat a mushroom from this page alone

Confirm identity using the whole specimen, multiple reputable sources, and a qualified local expert. Identified edible species still require appropriate preparation. Cooking does not make a poisonous mushroom safe.

Safety and poison response
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