Pisolithus arhizus

What You Should Know

Pisolithus arhizus or Pisolithus Tinctorius is a widespread earth-ball like fungus. This amazing mushroom starts out looking like a tough, walnut- to baseball-sized puffball, but eventually develops into a minor monstrosity that sticks up from the ground like a dusty stump.

Progressively from the top, the whole of the fruitbody turns into a soft mass of brown spore-bearing powder. At maturity, cracks appear in the upper surface and the spores blow away on the breeze or get washed away to new locations in wet weather.

Because it forms mycorrhizas with almost any kind of root, this ectomycorrhizal fungus is frequently used by foresters (and in recent years by gardeners, too) as the basis of a soil inoculant to promote tree and plant growth - particularly in the remediation of areas of degraded or polluted land or formerly clear-felled forest sites.

The black viscous gel is used as a natural dye for clothes. Pisolithus arhizus is a major component in mycorrhizal fungus mixtures that are used in gardening as powerful root stimulators.

Other names: Dead Man's Foot, Dyeball, Horse Dung Fungus, Perdebal, Bohemian Truffle.

Pisolithus arhizus Mushroom Identification

1. Ecology

   Mycorrhizal with various hardwoods and pines; growing alone, scattered, or in small groups; often found in gravel, sandy soil, in ditches, on lawns, and so on; summer and fall, or overwinter in warm climates; widely distributed in North America but more commonly found on the West Coast and in the southeast.

2. Fruiting Body

   4–10 cm high; 3–8 cm across; ball-shaped when young, with or without a stemlike base; stretching out with maturity to become top-shaped, tooth-shaped (like a giant molar), stumplike, widely cylindric, or just plain odd; outer surface at first brownish to yellowish, eventually breaking up to expose the interior; outer rind thin and fragile; interior at first packed with pea-sized, yellow to whitish or cinnamon-brown spore packages embedded in the blackish gel, disintegrating from the top downward to become a mass of cinnamon-brown spore dust (often gelatinous toward the base); stem-like base when present rudimentary and stubby; often with yellowish rhizomorphs attached.

3. Spore Print

   Cinnamon brown.

4. Microscopic Features

   Spores 5–8 µm excluding ornamentation; globose; densely echinate with isolated spines 1–2 µm long and about 0.5 µm wide at the base; thick-walled; golden in KOH.

Pisolithus arhizus Taxonomy and Etymology

This mushroom was described in 1786 by Italian mycologist Giovanni Antonio Scopoli. Treating it as a puffball, Scopoli gave this fungus the binomial scientific name Lycoperdon arrizon.

In 1801 Christiaan Hendrik Persoon retained (but with an 'h') the specific epithet when he included this species with other earthballs in the genus Scleroderma.

From 1928 this fungus was known (and still is in some modern field guides) as Pisolithus tinctorius - that specific epithet referring to its use in dyeing fabrics.

It was not until 1959 that the Dyeball became generally known by its current scientific name, which was proposed by German Stephan Rauschert (1931 - 1986).

The generic name Pisolithus comes from two Greek words: Piso- meaning a pea, and lith meaning a stone, while the specific epithet arrhizus means 'having no roots'. Pisolithus arrhizus therefore translates to rootless pea-stone.

Pisolithus arhizus How to Make Dye

Pour hot water into a jar, insert the mushroom, and if the color changes – ta da! The next step is to add a yarn sample to see how the dye will affect wool, cotton, or silk.

Pisolithus arhizus Synonyms

1. Lycoperdon arrizon Scop.

2. Scleroderma arhizum (Scop.) Pers.

3. Scleroderma tinctorium Pers.

4. Pisolithus arenarius Alb. & Schwein.

5. Lycoperdon capsuliferum Sowerby

6. Polysaccum olivaceum Fr.

7. Polysaccum pisocarpium Fr.

8. Pisolithus tinctorius (Pers.) Coker & Couch.