Collared earthstarGeastrum triplex
Expert-verifiedUpdated October 3, 2026
Passport
- Edibility
- Inedible
- Season
- Aug — Nov
- Hymenophore
- Chambered
- Cap color
- Cream
- Size
- Medium (5–15 cm)
- Smell
- Odorless
- Reviewed
- Yes ✓
Quick answers
Where to look?
Deciduous forest, Mixed forest
When does it appear?
Aug — Nov
Active months: August, September, October, November.
How to recognize it? Three signs
- Cap color: Cream, Brown, Grey
- Cap shape: Irregular
- Smell: Odorless
Fruiting season
August – November
Description
Collared earthstar (Geastrum triplex) is one of the most beautiful and memorable mushrooms of our forests. A young one looks like a small, hard bulb hidden in the leaf litter. When mature, the outer skin splits into 4-8 petal-like rays and opens out, turning into a star 5-10 cm across. In the center sits a round spore sac with a tiny pore on top. "Triple" (as its Ukrainian name says) because the skin has THREE layers, and the middle one forms a distinctive "collar" or "cup" around the spore sac. When it rains, drops hit the sac like a drum and puff a cloud of spores out through the pore — ancient evolution invented a rain-powered pneumatic pump.
This is an inedible mushroom — not poisonous, but a dead end in the kitchen: the flesh of a young mushroom is tough and corky, and in a mature one it turns into a powdery mass of spores. Its value is purely decorative — a real forest find for a photographer or a child. Dried fruiting bodies keep their "star" shape for years, and you can dry them for a herbarium. There is no evidence of either toxicity or culinary value.
In Ukraine it is unevenly distributed — uncommon, but easy to recognize. It grows in deciduous and mixed forests in the leaf litter under oak, beech, hornbeam and hazel. Forms mycorrhiza. Season — August–November. It loves shady, damp spots, forest edges and the slopes of wooded ravines. It is not listed in the Red Data Book of Ukraine, but is considered an indicator of well-preserved forest — in young plantations you will practically never see it.
Cap
A young mushroom is a round or egg-shaped fruiting body 2-5 cm across, firm, creamy white or ocher-cream, sunk in the litter. When mature, the outer skin splits from the top into 4-8 petal-like rays and folds back, forming a star 5-12 cm across. The rays are fleshy, spread out in damp weather and curling inward in dry weather. In the center is a round spore sac 1-3 cm across, smooth, grayish brown or chocolate gray, with a small round pore on top for releasing spores.
Hymenophore
The hymenophore is enclosed inside the spore sac (a gasteromycete). At first the flesh is white, soft. With age it turns grayish brown and becomes a powdery mass of spores. When mature, the spores escape through an apical pore — in the rain, drops hit the sac and puff out a cloud of spores.
Stem
There is no stem in the usual sense. In the "star" part, the fleshy middle layer forms a distinctive collar or cup around the base of the spore sac. This collar is the diagnostic feature of G. triplex that sets it apart from other earthstars.
Flesh
In a young fruiting body it is white, soft, with a layered structure. With age it shrinks, darkens and turns into a powdery mass of spores. It doesn't change color quickly when cut.
Smell
Faint, earthy, neutral. Not pronounced. The taste isn't tested — the mushroom is not edible.
Lookalikes
Related species
Mushrooms of the same genus and habitat — to study side by side and never mix up.
Bulbous honey fungus
Armillaria gallica
Dark honey fungus
Armillaria ostoyae
Poplar fieldcap
Cyclocybe aegerita
Ringless honey fungus
Desarmillaria tabescens
Agaricus abruptibulbus
Agaricus haemorrhoidarius
Agaricus haemorroidarius
Ashen chanterelle
Cantharellus cinereus
Blushing bolete
Leccinum roseofractum
Frequently asked questions
Can you eat it?
It isn't used as food. Not poisonous, but not edible either: the flesh is tough and corky even in a young mushroom, and in a mature one it's a powdery mass of spores. It is occasionally mentioned in folk medicine as a "substitute" for puffballs, but without any evidence that it works. No cuisine has a tradition of eating it.
Spores in the air — are they dangerous?
In normal amounts — no. If you step on a mature earthstar, it will puff out a noticeable cloud of spores. Harmless for a healthy person. People with chronic allergies or asthma are better off not breathing in the spores of any mushroom. In any case, don't sniff them up close.
Is it worth collecting for a herbarium?
Yes. Earthstars dry well and keep their star shape for years. Carefully cut a mature specimen together with the litter (keeping the lower part of the rays), dry it in the shade and store it in a box. A lovely addition to a natural history collection. But don't collect ALL the ones you find: leave a few in place so they can reproduce.
Where should you look for it?
In deciduous and mixed forests under oak, beech, hornbeam, hazel. It loves shady spots with a thick layer of leaf litter, forest edges, the slopes of wooded ravines and north-facing slopes. In young plantations and pine forests you will practically never see it. Most often — in old oak and beech forests.
Which regions of Ukraine is it found in?
Western Ukraine (the Carpathians, Prykarpattia), the Right-Bank and Left-Bank Forest-Steppe, Polissia (less often). In the Steppe — in ravine (bairak) woods. The most beautiful specimens are found in the virgin beech forests of the Carpathians. It is not in the Red Data Book, but is considered an indicator of well-preserved forest.
When should you look for it?
August — November, peaking in September–October. Young round fruiting bodies appear in August and open in September–October. Dry "stars" stay visible in the forest almost all winter — you can find them even under snow.
Can it be confused with something dangerous?
An opened earthstar can't be confused with anything dangerous — its shape is so recognizable that a mistake is ruled out. A young round earthstar can be confused with round young puffballs, but if you don't eat round mushrooms you can't identify, there's no risk. The Common earthball (Scleroderma) is poisonous, but it has a tough, yellow-ocher skin with small scales and never opens into a star.
How is it different from other earthstars?
The main feature of G. triplex is the distinctive collar around the base of the spore sac, formed by the middle layer. Other earthstars (G. saccatum, G. fimbriatum, G. quadrifidum) have no such collar, or it is barely noticeable. G. triplex is also the largest of Ukraine's earthstars (5-12 cm versus 2-5 cm for the rest).
Is Collared earthstar edible or poisonous?
What kind of spore-bearing surface does Collared earthstar have?
What does the cap of Collared earthstar look like?
What does the stem of Collared earthstar look like?
Sources
- [1]Вікіпедія (українська)
- [2]Атлас грибів України, Зеров Д.К. (1979)
- [3]MycoBank Database
- [4]Index Fungorum
- [5]GBIF
- [6]iNaturalist Ukraine