Part 18

Marginal cystidia: composed of chains of swollen, hyaline cells.

Facial cystidia: absent.

Habitat & Distribution: Found in birch-woods, less frequently collected in the vicinity of conifers; wide-spread and fairly common, but it is erratic in its appearance giving the impression of being absent from a locality until one season it suddenly fruits in profusion.

General Information: An easily recognised fungus because of its striking colour. It is also very familiar and well-known because it appears so often on Christmas cards, and features commonly in illustrations in children’s story-books. The fungus contains a poison which formerly was used to kill flies--hence the common name of ‘Fly agaric’ and the scientific name from the latin name for the house-fly. The red skin of the cap, where the major amount of the poison resides, was cut up with a little milk and sugar or honey; flies attracted to this sweet concoction inadvertently ate the poison and later perished. This fungus has a very well documented and long history and appears in the legends of many countries. It is featured in Greek mythology, Slavic and Scandinavian folk-lore and indeed appears in the pre-history of Indian tribes of N.E. Asia. It has even been connected with the formation of certain sects within the early Christian church.

Illustrations: F. frontispiece; Hvass 1; LH 117; NB 113¹; WD 2¹.

Notes on the genus Amanita

The genus Amanita contains many important mycorrhizal fungi including the ‘Blusher’, A. rubescens (Fries) S. F. Gray, the ‘Tawny grisette’, A. fulva Secretan, and the ‘False death-cap’, A. citrina S. F. Gray. The first grows on heaths and in woods with a variety of trees; A. fulva frequently grows with birch and A. citrina with several leafy trees although its var. alba (Gillet) E. J. Gilbert appears to be confined to beech woods. However, there is some evidence that many members of the genus in drier more southern countries than Britain, are non-mycorrhizal. In fact the genus as a whole may be southern-temperate in its distribution. In the British Isles the number of species of Amanita recorded decreases as one goes north, or the frequency of single species except for a few widespread forms falls off northwards. In a few cases a more familiar southern species is replaced in similar habitats by another species, e.g. A. phalloides (Fries) Secretan is replaced by A. virosa Secretan the ‘Destroying angel’ in Scotland, and A. citrina frequently in the north by A. porphyria (Fries) Secretan. Species of Amanita are usually large conspicuous fungi and the genus contains some of our best known agarics. One, A. muscaria (Fries) Hooker has already been mentioned, but the genus also includes the ‘Death-cap’ A. phalloides and ‘Caesar’s mushroom’ A. caesarea (Fries) Schweinitz, a fungus not found in this country but considered to be superior in edibility to all other fungi; thus edible and deadly poisonous species are found closely related and this simply emphasises how important it is not to eat the agarics one finds in the woods and fields except when accompanied by a ‘real’ expert. Deaths or near fatalities in Europe and North America are recorded annually due to the eating of fungi belonging to this genus.

The poisonous qualities of the fungi in this genus--only a very small amount of poison is often sufficient to produce fatal results--has led to a close connection between these fungi and black magic and the supernatural. This connection is even more emphasised when it is learnt that some have an intoxicating effect. Hence the long history mentioned earlier.

Members of the genus Amanita are characterised by their anatomy and certain macroscopic features; the former is illustrated under A. muscaria, i.e. the divergent gill-trama. The main macroscopic character of note is the presence of a volva at the base of the stem and it is the details of this volva which helps to distinguish different species. A. phalloides has a distinct, loose, membranous sheath, in A. citrina the volva is reduced to a narrow rim around the bulbous stem and in A. rubescens and A. muscaria the volva is simply a series of concentric zones of woolly scales. All the four species noted above possess a ring, but A. fulva the ‘Tawny grisette’ and A. vaginata (Fries) Vittadini the ‘Grisette’ only possess a volva; this has lead to the use of the generic name Amanitopsis in many books, now no longer considered necessary.

The veil in Amanita is probably the most highly developed amongst our common agarics and from Appendix iv it can be seen how the scaly cap and stem originate and how the volva differs from the ring. The volva and cap-scales constitute what has been called the universal veil and the ring which stretches from the cap margin to the stem has been termed the partial veil.

The spores of species of Amanita are large and their shape and chemical reactions help to distinguish the different species within the genus. One of the most interesting features, however, is that the spore-mass, although usually described as white, in many species is not white but flushed greenish grey, etc. The slight subtleties in colour of the spore-print assist in classification.

The following notes may be instructive in conjunction with the information above (for common names see above).

(i) Possessing a ring on the stem:--

~A. citrina~ S. F. Gray

Cap: width 55-80 mm. Stem: width 18-22 mm; length 70-80 mm.

A lemon-yellow or whitish capped agaric with bulbous stem-base, white patches of volva on cap and white stem with flesh strongly smelling of new potatoes.

Spores: almost globose and measuring 9-10 × 7-8 µm.

~A. excelsa~ (Fries) Kummer

Cap: width 75-140 mm. Stem: width 20-28 mm; length 85-120 mm.

A greyish or brownish capped agaric with clavate stem-base, grey patches of volva on the cap and white concentrically scaly stem with flesh unchanged on exposure to the air.

Spores: broadly ellipsoid and measuring 9-10 × 8-9 µm.

~A. rubescens~ (Fries) S. F. Gray

Cap: width 70-120 mm. Stem: width 12-25 mm; length 65-100 mm.

A reddish fawn or pinkish buff capped agaric with swollen stem-base, pinkish or flesh-coloured patches of volva on cap and reddish concentrically scaly stem with flesh becoming reddish when exposed to the air.

Spores: ellipsoid and measuring 9-10 × 5-6 µm.

~A. pantherina~ (Fries) Secretan

‘Panther’

Cap: width 48-95 mm. Stem: width 12-20 mm; length 65-100 mm.