Inocybe geophylla

Description

Inocybe geophylla is a poisonous mushroom of the genus Inocybe. It is widespread and common in Europe and North America, appearing under both conifer and deciduous trees in summer and autumn. The fruiting body is a small all-white or cream mushroom with a fibrous silky umbonate cap and adnexed gills.

Distinguishing features also include the small size, the spermatic odor (crush a piece of the cap between your fingers - but read this if you're having trouble figuring out that olfactory description), and the smooth, elliptical spores.

Inocybe geophylla var. lilacina has a purple cap.

Common names: Earthy Inocybe, White Fibrecap, Little White Inocybe.

Mushroom Identification

1. Ecology

   Mycorrhizal with hardwoods and conifers; growing alone, scattered, or gregariously; summer and fall (and winter in warm climates); widely distributed in North America.

2. Cap

   1-4 cm; conical at first, becoming broadly bell-shaped or broadly convex; dry; silky or almost smooth; whitish; the margin often splitting when mature.

3. Gills

   Attached to the stem, sometimes by a notch; close; whitish, becoming grayish brown and eventually medium brown; covered at first by a cob-webby white cortina.

4. Stem

   1-6 cm long; up to about .5 cm thick; more or less equal; dry; silky; whitish; fairly firm.

5. Flesh

   Whitish; insubstantial.

6. Odor

   Spermatic or sometimes not distinctive.

7. Chemical Reactions

   KOH on cap surface negative.

8. Spore Print

   Dull brown.

9. Microscopic Features

   Spores 8-10 x 4.5-6 µ; more or less elliptical; smooth. Cystidia up to 70 x 20 µ; fusoid or fusoid-ventricose, often with a flattened apex; abundant; thick-walled; apically encrusted.

10. Similar Species

    The White Fibrecap Inocybe geophylla could be confused with Agaricus campestris, which is usually much larger, has a stem ring and does not have a silky cap.

Inocybe geophylla Distribution & Habitat

Inocybe geophylla is common and widespread across Europe and North America. It is found under live oak, pine and Douglas fir. Both varieties are found in the Canadian Arctic regions of northern Manitoba and North West Territories. It is mycorrhizal, the fruiting bodies are found in deciduous and coniferous woodlands in summer and autumn. Within these locations, fruiting bodies may be found in grassy areas and near pathways, or often on rich, bare soil that has been disturbed at roadsides, and near ditches.

In Palestine, I. geophylla grows under Palestine oak (Quercus calliprinos) and pines, with mushrooms still appearing in periods of little or no rain as they are mycorrhizal.

In Western Australia, Brandon Matheny and Neale Bougher (2005) pointed to collections of what was referred to as I. geophylla var. lilacina by some Australian taxonomists, as a misapplication of the name I. geophylla var. lilacina; the specimens have been reclassified as the species Inocybe violaceocaulis.

History

The White Fibrecap was described scientifically in 1821 by Elias Magnus Fries, who gave it the binomial name Agaricus geophyllus.

In 1871 German mycologist Paul Kummer transferred this species to the genus Inocybe, establishing its currently accepted scientific name as Inocybe geophylla.

Synonyms of Inocybe geophylla include Agaricus geophyllus Fr., Agaricus clarkii Berk. & Broome, Inocybe clarkii (Berk. & Broome) Sacc., and Inocybe geophylla var. alba Hruby.

Inocybe, the genus name, means 'fibrous head', while the specific epithet geophylla is derived from the Ancient Greek words geo- meaning earth, and phyllon which means leaf.

Toxicity

Like many fibrecaps, Inocybe geophylla contains muscarine. The symptoms are those of muscarine poisoning, namely, greatly increased salivation, perspiration (sweating), and lacrimation (tear flow) within 15–30 minutes of ingestion. With large doses, these symptoms may be followed by abdominal pain, severe nausea, diarrhea, blurred vision, and labored breathing. Intoxication generally subsides within two hours. Delirium does not occur.

The specific antidote is atropine. Inducing vomiting to remove mushroom contents is also prudent due to the speed of onset of symptoms. Death has not been recorded as a result of consuming this species. It is often ignored by mushroom hunters because of its small size.

Photo sources:

Photo 1 - Author: James Lindsey (CC BY-SA 2.5)

Photo 2 - Author: Christine Braaten (wintersbefore) (CC BY-SA 3.0)

Photo 3 - Author: Richard Sullivan (enchplant) (CC BY-SA 3.0)

Photo 4 - Author: Richard Sullivan (enchplant) (CC BY-SA 3.0)