Amanita excelsa: The Ultimate Mushroom Guide

About The Amanita excelsa Mushroom

Sometimes referred to as the False Panthercap, Amanita excelsa is very variable in appearance and samples are sometimes mistakenly recorded as Panthercap, Amanita pantherina. Its most commonly cited synonym is Amanita spissa.

The Section Validae is characterized by basidiomata with a hyphal structure mostly sphaerocystic, crumbly, so that the general or universal veil protecting them during the first stage of growth (primary), when breaking, remains completely on the surface of the cap, in the form of small, powdery patches, which can easily disappear. The volva, almost absent, shows some small beads, adherent to the bulb (napiform-rooting volva). Non-striated cap margin. In this Section are found Amanitas with persistently white flesh and others with more or less reddening flesh, most of them are edible, after cooking, as they contain thermolabile toxic substances, between which the hemolysins, which are eliminated with the temperatures of 70-80 °C.

Amanita excelsa var. spissa is edible, but there is a serious risk of confusing it with the highly poisonous Amanita pantherina.

Amanita excelsa var. alba is inedible.

Other names: Grey Spotted Amanita.

Amanita excelsa Identification

1. Cap

   The cap of A. excelsa is 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

   The gills are 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

   The stem is 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.

Varieties of the Species

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

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

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

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

Amanita excelsa Taxonomy & Etymology

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. Synonyms of Amanita excelsa var. excelsa include Agaricus excelsus Fr., Agaricus excelsus var. cariosus Fr., Agaricus validus Fr., Amanita cariosa (Fr.) Gillet, Amanita excelsa (Fr.) P. Kumm., and Amanita spissa var. valida (Fr.) E.-J. Gilbert.

Two varieties of Amanita excelsa occur in Britain: Amanita excelsa var. excelsa (Fr.) P. Kumm. (syn. Amanita spissa (Fr.) Opiz), and Amanita excelsa var. spissa (Fr.) Neville & Poumarat.

(Amanita spissa var. valida (Fr.) E.-J. Gilbert is a synonym of Amanita excelsa var. spissa (Fr.) Neville & Poumarat.) The two varieties are similar in colour but Amanita excelsa var. spissa is the more robust of the two forms (and in Britain and Ireland the more common) and is said by some to smell faintly of radish when the flesh is cut. Most of the pictures shown on this page are of Amanita excelsa var. spissa, but the specimens seen here are probably of Amanita excelsa var. excelsa, having pale caps and and, when cut, smelling slightly of radish. Separating the two varieties is difficult, however, and many authorities still treat them as merely minor form differences.

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.

Although the stem flesh of Amanita excelsa (both varieties) does not turn pink when cut or bruised as the Blusher Amanita rubescens does, some people refer to these mushrooms as the European False Blusher. In stature they have much more in common with Blushers than with Panthercaps, the origin of their former common name False Panthercap.