Scleroderma areolatum

What You Should Know

Scleroderma areolatum is a poisonous basidiomycete mushroom and a member of the genus Scleroderm.

Like most members of Scleroderma, S. areolatum resembles but is only distantly related to the giant puffball. It can be distinguished from the giant puffball by cutting it in half; the puffball will have a solid, denser middle, with no signs of a developing cap mushroom. They are usually 1–5 cm in diameter and grow individually or in small groups. They are commonly found in deciduous forests, in neutral soil.

The ingestion can lead to vomiting, diarrhea, and in larger quantities, fainting.

Other names: Leopard Earthball, Earth Balls.

Scleroderma areolatum Mushroom Identification

1. Ecology

   Mycorrhizal with hardwoods and conifers in moist, shady woods - but also possibly saprobic, since it is also found in open areas, gardens, and so on; growing gregariously or clustered (rarely alone); widely distributed in North America; summer and fall.

2. Fruiting Body

   1-5 cm across; round or shaped like an inverted pear; the surface smooth and bruising reddish when young, becoming scaly (especially near the apex) and by maturity acquiring a "leopard skin" appearance with small brownish scales over a yellowish base color; skin 1 mm thick or less; without a stem, or occasionally with a poorly defined pseudo-stem; with white rhizomorphs attached to the base; odor sweetish or not distinctive.

3. Spore Mass

   Whitish and fleshy at first but soon dark purplish or olive-brown, eventually powdery.

4. Chemical Reactions

   Surface instantly yellowish-brown or dark red with KOH.

5. Microscopic Features

   Spores 11-15 µ; round or nearly so; densely spiny but not reticulate; with spines up to 2 µ long.

Scleroderma areolatum Look-Alikes

1. Lycoperdon perlatum

   The common puffball has pearly, pointed scales and is very spongy to the touch. It is club-like in shape has a rudimentary infertile stipe.

2. Lycoperdon mammiforme

   Another of the many puffball species is white at first before its surface breaks up into large cream scales rather than warts; it, too, is more spongy and is more pear-shaped, comprising a fertile ball on a spongy infertile stipe.

Scleroderma areolatum Taxonomy and Etymology

This fungus was first validly described in the scientific literature in 1818 by German naturalist Christian Gottfried Ehrenberg (1795 - 1876), who gave it the binomial scientific name Scleroderma areolatum. That still remains its generally accepted name.

Synonyms of Scleroderma areolatum include Scleroderma lycoperdoides Schwein.

The generic name Scleroderma comes from the Greek words scler- meaning hard, and -derma meaning skin.

The specific epithet areolatum comes from the Latin noun areola, which means the small circular region around a nipple - a reference, therefore, to the pale annular region around each scale on the surface of this earthball - like the spots on a leopard.

Sources:

Photo 1 - Author: Rudolphous (Creative Commons Attribution-Share Alike 4.0 International)

Photo 2 - Author: Rudolphous (Creative Commons Attribution-Share Alike 4.0 International)

Photo 3 - Author: Rudolphous (Creative Commons Attribution-Share Alike 4.0 International)

Photo 4 - Author: Björn S. (Creative Commons Attribution-Share Alike 3.0 Unported)