Where does Scleroderma citrinum grow?

It grows in woodlands, heathlands, sandy soils, and garden edges. It is an ectomycorrhizal fungus that forms relationships with tree roots, commonly found near oak, birch, and pine trees.

ToxicHigh Misidentification RiskSpecies Guide

Scleroderma citrinum (Earthball Mushroom) – Identification, Toxicity & Lookalikes

Q: How do you tell if it is an earthball or puffball?

Cut it open vertically. An earthball (Scleroderma citrinum) has a dark purple-black marbled interior and thick tough skin. An edible puffball has a pure white interior and thin smooth skin when young.

Q: Can AI identify earthball mushrooms?

Yes, AI mushroom identification tools can help detect earthball mushrooms from images by analyzing the round shape, warty surface texture, and color. However, the most reliable test is cutting the mushroom open to check the interior color, which requires physical examination.

Paul Stamets

Mycologist · Author · Fungi Expert

Updated

Apr 11, 2026

4.0k views

Scleroderma citrinum, commonly known as the earthball mushroom, is a toxic, puffball-like fungus found in woodlands, gardens, and sandy soils across many parts of the world. Unlike true puffballs, it has a thick, tough outer skin and dark, purplish-black spore mass inside. It is not edible and can cause gastrointestinal poisoning if consumed. Proper identification is essential because beginners often confuse it with edible puffballs.

Scleroderma citrinum earthball mushroom identification — round yellowish-brown specimen with warty surface — Photo: Jorg Hempel, CC BY-SA 2.0 DE, via Wikimedia Commons

Scientific Classification & Taxonomy

Kingdom	Fungi
Phylum	Basidiomycota
Class	Agaricomycetes
Order	Boletales
Family	Sclerodermataceae
Genus	Scleroderma
Species	Scleroderma citrinum

Related to other earthball species and distinct from true puffballs like Lycoperdon. Despite its superficial resemblance to edible puffballs, Scleroderma citrinum belongs to a completely different order (Boletales), highlighting why visual identification alone is unreliable.

Key Features (Identification Essentials)

Outer Appearance (Peridium)

Color: Yellowish to brown
Surface: Rough, cracked, wart-like texture
Shape: Round or irregular (2–10 cm wide)
Skin: Thick and tough — much thicker than edible puffball skin

Interior (Gleba) — Critical ID Feature

Young: White, quickly darkening
Mature: Dark purple to black with white veins (marbled appearance)
Not uniform like the pure white interior of edible puffballs

⚠️

Always cut open any puffball-like mushroom before consuming. If the interior is dark, marbled, or anything other than pure white — it is not an edible puffball. This simple cross-section test is the safest way to avoid earthball poisoning.

Structure

Thick, tough outer skin (peridium)
No visible stem (or very short, rudimentary base)
Attached to soil by root-like mycelial cords

Scleroderma citrinum cross-section showing dark purple-black spore mass interior — earthball vs puffball identification — Cross-section showing dark spore mass. Photo: Hans-Martin Scheibner, CC BY-SA 3.0, via Wikimedia Commons

Smell, Taste & Texture

Smell

Slightly unpleasant or rubbery
Earthy, sometimes metallic

Taste

Not recommended (toxic)
⚠️ Never taste wild mushrooms

Texture

Hard, tough outer skin
Powdery spore mass inside when mature
Firm and dense when young

Physical Dimensions & Structure

2–10 cm

Diameter

Round, irregular

Shape

Thick & tough

Skin Thickness

Dark, powdery spores

Interior

Environment & Habitat

Habitat

Woodlands and heathlands
Sandy soils
Garden edges and paths

Seasonality

Summer to late autumn
Appears after warm rain

Growth Pattern

Singly or in clusters
Often near tree roots (ectomycorrhizal)

Geographic Distribution

United KingdomUnited StatesEuropeAsiaWidely distributed in temperate regions

Scleroderma citrinum growing in woodland habitat — common earthball near tree roots on forest floor — Scleroderma citrinum in woodland habitat, UK. Photo: Stu's Images, CC BY-SA 3.0, via Wikimedia Commons

Toxicity & Health Risks

❌

Not Edible

Causes GI illness

🟠

Moderate Toxicity

Gastrointestinal irritation

🟢

Low Fatality Risk

Rarely fatal

Toxic Effects

Causes gastrointestinal irritation through toxic compounds in the flesh and spores.

Symptoms of Poisoning

Nausea and vomiting
Diarrhea
Abdominal discomfort and cramping

Onset Time

Usually within a few hours after ingestion.

⚠️

Rarely fatal but unpleasant and avoidable. The key to prevention is always cutting open any puffball-like mushroom before consumption — if the interior is not pure white, do not eat it.

Risk Level Assessment

Toxicity	🟠 Moderate
Fatality Risk	🟢 Low
Misidentification Risk	🔴 High
Edibility	❌ Not edible

Similar Species (Critical Comparison)

Feature	Earthball (S. citrinum)	True Puffball (Edible)
Interior	Dark, marbled	Pure white (young)
Skin	Thick, rough	Thin, smooth
Toxicity	Toxic ☠️	Edible ✓
Texture	Firm, tough	Soft, spongy
Spore Color	Dark purple-black	Olive-brown

Common Lookalikes

Lycoperdon perlatum (Common Puffball) — edible when young and white inside
Bovista species — edible, thin-skinned, white interior
Other Scleroderma species — also toxic, similar appearance

⚠️

Always cut open any puffball-like mushroom before eating. This is the safest and most reliable test — pure white interior means edible puffball; dark or marbled interior means toxic earthball.

Growth Pattern & Life Cycle

Ecological Role

Ectomycorrhizal fungus
Forms symbiotic relationships with tree roots
Helps trees absorb water and nutrients

Life Cycle

Spore release through cracks in outer skin
Mycelium connects with tree roots
Fruiting body develops at soil surface
Spores disperse through wind and rain

Economic & Ecological Value

Ecological Importance

Supports forest ecosystems through mycorrhizal networks
Improves soil health and structure
Helps trees grow through symbiotic nutrient exchange

Economic Value

No culinary value (toxic)
Studied for ecological roles in forestry
Important in mycology education

Pros and Cons

Pros

✓ Important ecological role in forest ecosystems
✓ Easy to recognize with practice (thick skin + dark interior)
✓ Helps tree nutrient cycles through mycorrhizal networks

Cons

✗ Toxic and inedible
✗ Easily confused with edible puffballs by beginners
✗ Can cause gastrointestinal illness if consumed

How to Identify Scleroderma citrinum Safely

1Check the outer skin — rough, thick, and wart-like texture indicates earthball

2Cut open vertically — dark purple-black marbled interior confirms it is NOT an edible puffball

3Observe growth location — near tree roots in woodlands or sandy soils

4Avoid if interior is not pure white — only puffballs with a completely white interior are safe to eat

For better accuracy, use a wild mushroom identifier tool or AI-based mushroom identification app to confirm findings. Always verify with the cross-section test.

Expert Identification Tips

Always slice the mushroom vertically to check interior color
Never rely on outer appearance alone — thick skin is a clue but not definitive
Check internal color carefully — any darkness means toxic
Cross-reference with multiple features before deciding

Frequently Asked Questions

Is earthball mushroom edible?+

No, Scleroderma citrinum is toxic and should not be eaten. It causes gastrointestinal symptoms including nausea, vomiting, diarrhea, and abdominal discomfort.

How do you tell if it is an earthball or puffball?+

Cut it open vertically. An earthball has a dark purple-black marbled interior and thick tough skin. An edible puffball has a pure white interior and thin smooth skin when young.

Can Scleroderma citrinum kill you?+

It is rarely fatal but causes unpleasant gastrointestinal illness including nausea, vomiting, and diarrhea. Medical attention should be sought if consumed.

Where does it grow?+

In woodlands, heathlands, sandy soils, and garden edges. It is an ectomycorrhizal fungus commonly found near oak, birch, and pine trees.

What happens if you eat it?+

You may experience nausea, vomiting, diarrhea, and stomach pain. Symptoms usually appear within a few hours of ingestion.

Can AI identify earthball mushrooms?+

Yes, AI tools can help detect earthball mushrooms from images by analyzing the round shape, warty surface, and color. However, the most reliable test is cutting the mushroom open to check the interior, which requires physical examination.

Final Thoughts

Scleroderma citrinum is a common but often misunderstood mushroom that can easily be mistaken for edible puffballs. Its dark interior, tough skin, and toxic nature make it important to identify correctly.

Combining field knowledge with a reliable mushroom identifier tool ensures safer exploration and helps prevent accidental poisoning.

Learn more about mushroom anatomy and identification features to build your knowledge, or explore our recommended mushroom identification books for in-depth field guides.

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