er. 



Order Hymenomtcetes. Tribe Pileati. 



Plate XXVII. 



AGARICUS MUTABILIS, sch^ff. 



Variable Stump Agaric. 

 Series Derminus. Subgenus PnoLiOTA. 



Spec. Char. A. mutabilis. Very variable iu size, densely fasciculate. Pileus slightly flesliy, smooth, ex- 

 panded, obtusely umbonate, the centre rich yeDow-brown or bright tawny at full growth, the margin thin, trans- 

 parent, cinnamon, turning paler when dry. Gills subdecurrent, close, broad, pale umber, then ferruginous from the 

 spores. Flesh white. Stem slender, fistulose, dark brown, smooth above or minutely pulverulent and pale, 

 squamulose below. Ring woven, suberect, not fugacious, in age detlexed and striate, stained with the spores. 

 Smell and flavour very rich and agreeable ; when raw resembling A. oreades. Esculent. 

 AoAifTCUS mutabilis, Scliipffer, Fries, Berkeley. 



marginatus, Batsch. 



caudicinus, Trattbiick, Fersoon. 



— annularis, 543, 0. P., Bulliard. 



Hah. On much-decayed stumps of various trees, particularly Lime. Perennial ; springing after electric rains at 

 any period from spring to autumn. Not common. 



Ill a youthful state, with the veil unbrokeu, we have known this Agaric to be mistaken for A. melleus, 

 which grows iu similar dense tufts from stumps. If the student be iu any doubt as to which of the two 

 has been found, a little patience, if the spores are uot yet ripened, will soon decide the question, by that 

 unfailing test, their colour ; those of A. melleus being white, while A. mutabilis deposits a })rofusion of 

 rusty-browu ones. Deposit is, however, scarcely a correct term, since the dust is exploded to a considerable 

 distance around the pileus of most Agarics. In an aged state, groups of A. midabilis may be seen of one 

 uniform rich brown hue, being coated with the spores they have shed upon each other. They often grow 

 tier above tier in fascicles in the interior of a rotten stump, and do not bend aside in a decumbent manner 

 till lax in decay. Buifs and browus are the tones of colour of this Agaric without any genuine uuraixed 

 yellow tinge, which will distinguish it from A. aureus, A. aurivellus, or any other golden-hued ones be- 

 longing to the same division. In the youthful state the pretty scaly stem and perfect veil, with a neat 

 little brown head, render our A. mutabilis a very elegant object ; when fully developed and saturated with 

 moisture the thin disc of the pileus becomes dark, while the fleshy central umbo remains of the bright 

 original hue ; this gives masses of tlie Agaric a very curious appearance. In early spring the proportions 

 of A. mufabilis differ much from those they attain in the dog-days, a high temperature causing them to 

 grow much faster, taller, and consequently more slender and less fleshy. In the drawing the left-hand 



