Myriostoma coliforme

What You Should Know

Myriostoma coliforme is an inedible rare earthstar mushroom. The fruit bodies start their development underground or are buried in leaf debris, linked to a strand of mycelium at the base. As they mature, the exoperidium (the outer tissue layer of the peridium) splits open into 7 to 14 rays which curve backward; this pushes the fruit body above the substrate. It is gray-brown and minutely roughened with small, lightly interconnected warts.

Fruit bodies grow grouped in well-drained or sandy soil, often in the partial shade of trees. The species occurs in deciduous forests and mixed forests, gardens, along hedges and grassy road banks, and grazed grasslands. Habitat on mainland Europe, where its known range extends from Scandinavia right down to the Mediterranean. This unusual earthstar is also known to occur in Asia, Africa, and the Americas.

Other names: Pepper Pot, Srebrna zvezdica (Serbian), Gwiazda Wieloporowata (Poland), Mnohokrčka Dierkovaná (Slovakia), Peperbus (Netherlands), Sieberdstern, Siebstern, Vielstieliger Siebstern (Austria).

Myriostoma coliforme Mushroom Identification

1. Fruitbody

   As with other earthstars the fruitbody comprises a mass of spore-bearing gleba encased in a two-layer skin. Young fruitbodies are slightly flattened (oblate) spheroids and very variable in size but generally between 3 and 8cm across.

2. Exoperidium

   The exoperidium, which is about 5mm thick, splits into several more or less equal-sized pointed rays (generally between 5 and 12 but occasionally more). Subspherical (an oblate spheroid), the spore sac is 1.5 to 5cm in diameter, grayish brown and with several irregularly spaced roundish ostioles up to 3mm in diameter via which spores emerge.

3. Gleba

   The gleba, which is brown and powdery when fully mature, is released into the air when raindrops hit the endoperidium. When fully expanded, the outer diameter (across the rays) is usually 5-10cm but exceptionally 12cm; however, once the rays curl back they often tuck beneath the fruitbody and raise the spore sac so improving spore distribution.

4. Stem

   The spore sac is connected to the base by a short multi-columned stem typically 5ch tall.

5. Spores

   Globose, 4-5µm in diameter (excluding warts); ornamented with numerous irregular warts up to 2um tall; inamyloid.

6. Spore Mass

   Brown.

7. Odor and Taste

   Not significant.

8. Habitat

   Found in leaf-litter-rich soil in deciduous and mixed woodland, particularly under Hazel in dry hedgerows.

9. Season

   Autumn to winter months.

Myriostoma coliforme Taxonomy and Etymology

The species was described in 1785 by Scottish naturalist James Dickson (1738-1822), who established the basionym when he named it Lycoperdon coliforme (in effect - Classifying it as a puffball). The currently-accepted scientific name Myriostoma coliforme dates from an 1842 publication by the Czech mycologist August Carl Joseph Corda (1809–1849).

Myriostoma, the generic name, is a reference to the many (myriad) openings (stoma comes from Greek and means a mouth or an opening) via which spores are ejected from the mature fruitbodies. The specific epithet coliforme comes from the Latin noun colum, meaning a strainer, and hence can be interpreted as 'in the form of a colander'.

Myriostoma coliforme Synonyms

1. Geastrum coliformis (Dicks.) Pers.

2. Myriostoma anglicum Desv.

3. Polystoma coliforme (Dicks.) Gray

4. Geastrum columnatum Lév.

5. Bovistoides simplex Lloyd.

6. Lycoperdon coliforme Dicks., Bot. Arr. Brit. Pl., Edn 2 2: 783 (1776)

Sources:

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

Photo 2 - Author: zaca (Creative Commons Attribution-Share Alike 3.0 Unported)

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

Photo 4 - Author: Glen van Niekerk (primordius) (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 5 - Author: jade fortnash (Public Domain)