Gymnopus fusipes

What You Should Know

Gymnopus fusipes (formerly often called Collybia fusipes) is a parasitic species of gilled mushroom that is quite common in Europe and often grows in large clumps. It is variable but easy to recognize because the stipe soon becomes distinctively tough, bloated, and ridged.

The distinctive spindle-shaped stem of this mushroom is often buried and visible only after excavation.

This mushroom occurs in tufts nearly always on the basal roots of hardwood trees, notably Beech and oaks, although very occasionally this species is reported growing on the roots of conifers. Another helpful identification feature of Gymnopus fusipes is their very wide gill spacing - far wider than other 'toughshanks'. (The tiny parasitic fungi on the gills pictured here are Spinellus fusiger.)

Most authors do not consider this species worthwhile for the table, but although this mushroom soon becomes tough, the caps (only) are said to be edible and good when young. Note that with its resistant texture G. fusipes can often appear collectible after several months of growth, but due to the normal development of organisms of putrescence during that time, such specimens could cause gastro-enteritis. Any rancid smell is a sign that the mushrooms are too old.

It is a serious parasite of oak trees, causing a root rot.

Other names: Spindleshank.

Gymnopus fusipes Mushroom Identification

1. Cap

   Convex, flattening with an irregular incurved margin at least until fully mature; 3 to 7cm across; brown, often with dark brown blotches.

2. Gills

   White, tinged tan-brown, developing rusty spots; adnexed or free; very widely spaced.

3. Stem

   White near the apex, tan towards the base; spindle-shaped and usually grooved and sometimes lined longitudinally; 7 to 15cm long and 0.8 to 1.5cm diameter; no stem ring.

4. Spores

   Ellipsoidal to pip-shaped, smooth, thin-walled, 4-6 x 2-3μm; hyaline.

5. Spore Print

   White.

6. Habitat & Ecological Role

   Parasitic/saprobic on the basal roots of mainly hardwood trees, especially oaks and less commonly Beech.

7. Season

   July to October; several weeks later in southern Europe.

Gymnopus fusipes Taxonomy and Etymology

The basionym of this species dates from 1791, when French mycologist Jean Baptiste Francois (Pierre) Bulliard described Spindleshanks and gave them the scientific name Agaricus fusipes. (In those early days of fungus taxonomy, most of the gilled mushrooms were included initially in the genus Agaricus!) It was the British mycologist Samuel Frederick Gray (1766 - 1828) who in 1821 transferred this mushroom to the genus Gymnopus, thereby creating the binomial name Gymnopus fusipes by which Spindleshank is generally accepted today.

Until quite recently most field guides referred to Spindleshanks by the scientific name Collybia fusipes, a name given to this species by Lucien Quelet in 1872, and many authoritative online sources do not yet reflect the recent redistribution of many former Collybia species to other genera such as Gymnopus and Rhodocollybia.

Synonyms of Gymnopus fusipes include Agaricus crassipes Schaeff., Agaricus oedematopus Schaeff., Agaricus contortus Bull., Agaricus fusiformis Bull., Agaricus fusipes Bull., Collybia crassipes (Schaeff.) P. Kumm., Collybia fusipes (Bull.) Quél., Agaricus lancipes Fr., Collybia lancipes (Fr.) Gillet, Collybia oedematopoda (Schaeff.) Sacc.,and Rhodocollybia fusipes (Bull.) Romagn.

Gymnopus, the generic name, comes from Gymn- meaning naked or bare, and -pus meaning foot (or, in the case of a mushroom, stem). The specific epithet fusipes means ' with spindle-shaped stems', and indeed most often the stems are centrally swollen and taper sharply towards the base - particularly so when, as is most often the case, these mushrooms occur in tufts rather than singly.

Sources:

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