Amanita excelsa

Description

Amanita excelsa is a species of fungus in the family Amanitaceae. The cap is gray-silver to light brown and covered in off-white to gray patch scales. Spherical to convex to flat. The stem is white with an obvious skirt and the bottom of the stem is bulbous rather than appearing from a volva. It is found in Asia, Europe, and North America, where it grows in deciduous forests.

In most guidelines, it is described as an edible member of the Amanita family. They must be thoroughly cooked before consumption, some toxins are destroyed by heat. The taste and texture are pleasant but due to the risk of confusing them with deadly Amanitas, Ultimate Mushroom does not recommend collecting and eating this fungus.

Common names: Gray Spotted Amanita, False Panthercap, Gray Warted Amanita.

Mushroom Identification

1. Cap

   50 - 120 (-150) mm wide, gray-brown or umber-brown or olive-brown, hemispheric when young, convex, then plane, with an incurved and nonstriate margin. The cap is initially covered with a volva, which on expansion of the cap, disrupts into thin, mealy, gray, irregular patches of volval tissue which are easily removable. The cap flesh is white and rather thick above the stem.

2. Gills

   Crowded, white, adnexed, 4 - 9 mm broad, with an undecorated to finely flocculose edge. Short gills are present in sets of one to three between every pair of full-length gills.

3. Stem

   60 - 120 (-150) × 15 - 30 mm, slightly narrowing upward, solid, white to pale gray and striate above the ring. It is covered with inconspicuous, white to pale gray, granular scales below the ring, which form concentric circles towards the base. The base is enlarged to a bulb up to 40 mm wide but can sometimes be barely broader than the stem when the stem is fully expanded. The ring is membranous, skirt-like, with the upper surface striate. The volva is present as 2 - 5 pale ocher brown zones of friable material above the bulb. The flesh is firm.

4. Odor and Taste

   Odor is faintly grass-like according to some European authors. Other European authors say it has a faint odor or taste of radish.

5. Spores

   The spores measure, according to Neville and Poumarat, (7.0-) 7.5 - 10.0 (-13.5) × (5.0-) 5.5 - 7.0 (-8.0) µm and are broadly ellipsoid to ellipsoid, occasionally elongate and amyloid. Clamps are absent at bases of basidia.

6. Spore Print

   White.

7. Habitat

   It is mycorrhizal with quite a few different trees including, oak, birch, chestnut, spruce and pine. Most often found along the edges of woodlands.

8. Season

   July to November.

Look-Alikes

1. Amanita citrina

   There is a white pouch residue on a white or light-colored grapefruit cap, but it is not pyramidal. It has a fragile pendent ring.

2. Amanita strobiliformis

   Has a wart-like white cap with tattered veil fragments hanging from the brim. Adult species have a ceiling that is domed rather than flat.

3. Amanita pantherina

   This mushroom can be avoided by very carefully studying the skirt on the stem.

4. Amanita rubescens

   Could also look similar but its flesh bruises red. The Blusher is also edible.

History

Described in 1821 and named Agaricus excelsus by the great Swedish mycologist Elias Magnus Fries, this mushroom was placed in the Amanita genus by Paul Kummer in 1871 and renamed Amanita excelsa.

The specific epithet excelsa is a Latin adjective that translates to elevated or lofty, while spissa means dense or crowded - a reference to the closely-spaced gills of these fungi.

Varieties:

1. Amanita spissa for. alba (Gilbert) Gilbert, identical to the type, but completely white.

2. Amanita spissa var. valida (Fries) Dörfelt & Roth = Amanita valida (Fr.) Quélet, which has a more brown-gray universal veil and browning flesh.

3. Amanita spissa var. excelsa (Fries:Fries) Dörfelt & Roth (= Amanita ampla Persoon), more slender than the type, with more rooting base and almost absent warts.

4. Amanita spissa var. cariosa (Fries) Gilbert = Amanita cariosa (Fr.) Quélet, similar to the previous, with almost hollow stipe, more rare species.

Synonyms

1. Venenarius excelsus (Fr.) Murrill, 1948

2. Amanita spissa var. excelsa (Fr.) Dörfelt & I.L. Roth, 1982

3. Amanita ampla Pers., 1801

4. Amanita solida Ferry, 1890

5. Amanita raphaniodora Ferry, 1890

6. Amanita spissa (Fr.) Bertill., 1866

7. Amanita cariosa (Fr.) Quél., 1880

8. Amanita valida (Fr. ex) Bertill., 1866

9. Amplariella valida (Bertill.) A.G.Parrot, 1960

Photo sources:

Photo 1 - Author: A.excelsa (CC BY 3.0)

Photo 2 - Author: Björn S... (CC BY-SA 2.0)

Photo 3 - Author: Jerzy Opioła (CC BY-SA 3.0)

Photo 4 - Author: Jerzy Opioła (CC BY-SA 3.0)

Photo 5 - Author: Holger Krisp (CC BY 3.0)