Agaricus augustus    Fr. 

common name(s) : The Prince 

New classification: Basidiomycota/Agaricomycotina/Agaricomycetes/Agaricomycetidae/Agaricales/Agaricaceae  
Former classification: Basidiomycota/Homobasidiomycetes/Agaricomycetideae/Agaricales/Agaricaceae/Agariceae  

synonyms: Psalliota augusta 
(unconfirmed synonyms: Agaricus subrufescens)  

edibility : edible, good

photo gallery of  Agaricus augustus
photo gallery of  Agaricus augustus potential confusions with  Agaricus augustus toxicity of Agaricus augustus genus Agaricus  

The cap is fleshy, firm, first hemispherical then convex and finally expanded, flattened or slightly curved at the centre. It is densely covered with brown or reddish triangular, fluffy, non protruding scales. They are arranged in more or less concentric circles, on a cream yellowish background, the cap centre being chestnut brown. Its surface is dry to slightly greasy; its margin is with veil flakes. The cap surface is scaly.

The stem is robust, cylindrical, swollen or club-shaped at the base, and deeply buried in the ground. It is full, sometimes becoming slightly hollow. It is white, sometimes pink above the ring, and with a smooth surface, white washed with red, and scales or flakes below the ring, turning brown with age. It has a white ring, superior, large, membranous and hanging, doubled, with a cog-wheel pattern on the inferior side, yellow-brown flakes/scales on the upper side, white and silky elsewhere.

The flesh is thick, compact, firm. It is white, turning yellow when cut (then turning brown), sometimes turning red at the stem base. The whole mushroom turns yellow when touched or bruised; its taste is mild, mushroomy, not distinctive; the odour is strong, complex, like a mixture of bitter almonds and aniseed; its texture is fibrous.

The gills are pale grey to white, then pink, then chocolate brown to black, free, narrow and very crowded . The spore print is chocolate brown. This species is saprophytic. It grows on the ground, on rich soils, in forest edges or grasslands (conifers or broad-leaved trees), in parks and gardens, where it appears isolated or in small troops, on sandy and calcareous grounds. This occasional species grows during summer and autumn, on a rather calcareous and sandy soil.

The fruiting period takes place from July to December.
Dimensions: width of cap approximately 16 cm (between 5 and 25 cm)
  height of stem approximately 15 cm (between 6 and 25 cm)
  thickness of stem (at largest section) approximately 25 mm (between 2 and 50 mm)

Chemical tests : positive reaction to Schaeffer's test.

Distinctive features : Large sized, scaly cap; stem white above ring, but with brown flakes or scales below ring; stem turning yellow when touched; odour of bitter almonds or aniseed; flesh turning weakly yellow or red when exposed to air, turning pink at stem base; on rich soils

Agaricus augustus is quite rare and confined in the forest of Rambouillet, and is occasional, more generally speaking .
here should be the distribution map of Agaricus augustus in the forest of Rambouillet
Above : distribution map of Agaricus augustus in the forest of Rambouillet



page updated on 14/01/18