7S0 THE AGARICACEAE OP MICHIGAN 



horny and shining, or dull opaque and pruinose or hairy. It is 

 delicate and filiform in the smaller forms. The SPORES with very 

 few exceptions are smooth. It seems to be a marked characteristic 

 of lliis genus, that the immature spores are easily loosened when 

 sections of the gills are mounted in water. The result is that 

 abundant immature spores are present in a mount, and great care 

 must be taken to get the measurements from mature spores. The 

 immature spores are usually delicately punctate-granular or ir- 

 regular in shape but practice will soon make the observer properly 

 discriminating. The spores of different species vary from spherical 

 to oval or elliptical, and are white when deposited in a mass. 

 In M. lasiosperma the spores are rough with short knobs. The 

 ODOR of some species is alkaline or nitrons, sometimes of radish, 

 and when collecting it is well to test the fresh plant, since the 

 odor may disappear. If the plants are kept in a tight box till one 

 gets home, the odor is often very marked on opening the box. 

 Omission to test for -the odor may make it difficult to identify the 

 plant correctly. 



My cen as may be found from early spring until the late autumn. 

 They are usually gregarious or eaespitose, and the wood-inhabiting 

 species often form dense clusters of individuals. .Many are quite 

 small, and are hidden among leaves, sticks and grass. The caps 

 of others reach a size of one or two inches. 



The genus was divided by Fries (in Hymen. Europ.) into nine 

 sections, largely with reference to the characters of the stem. 

 These divisions have been found so fundamental and satisfactory 

 that most later mycologists have followed the Friesian arrange- 

 ment. The nine sections are characterized in the key, and in the 

 text following. 



Key to the Species 



I. Stein with a colored or milky juice, (Lactipedes) (A). 



I. Stem without colored juice, II. 



II. Stem viscous, (Glutinipedes) (B). 



II. Stem not viscous, III. 



III. Base of stem dilated into a disk or bulb; pileus white or delicately 



tinted, 4-10 mm. broad, (Basipedes) (C). 



III. Base of stem not with abrupt bulb or disk, IV. 



IV. Edge of gills darker-colored from colored cvstidia, (Calodontes) 



(D). 



IV. Edge of gills not of a different color, V. 



V. Stem inserted by the naked base on the wood, leaves, etc., from which 



it grows, (Instititiae) (E). 



V. Stem attached by a villose or fibrilose more or less rooting base, VI. 



VI. Gills remaining clear white; mostly on the ground; pileus rarely 



above 1 cm. broad, white or brightly colored, (Adonidae) 

 (F). 

 VI. Gills tending to ashy, fuscous or flesh tints in age, VII. 



