THE AGARICACEAE OF TROPICAL NORTH 

 AMERICA— III 



William A. Murrill 



The introductory remarks used in the last article of this series 

 apply in a general way to the genera here treated ; most of them 

 belong to temperate regions and are scantily represented in the 

 tropics except at high elevations. The genus Hydrocybe seems 

 to delight in the moist mountain tops where tree-ferns grow, and 

 a number of endemic species have been developed in these peculiar 

 and segregated localities. It was my good fortune to be admir- 

 ably situated at Cinchona, Jamaica, at 5,000 feet elevation, for the 

 study of many species of this genus, and to have Mrs. Murrill 

 with me to make colored drawings from the freshly gathered 

 specimens. 



The following simple key may be used to distinguish these 

 genera. They all contain fleshy, central-stemmed species, but 

 none of them possess a volva and only two are furnished with 

 the rudiments of an annulus. The temperate species far exceed 

 those of the tropics, both in number and abundance. 



Lamellae fleshy, not waxy, though apparently so in Laccaria. 



Lamellae adnate ; spores echinulate. 1. Laccaria. 

 Lamellae decurrent. 



Sporophore solitary or gregarious. 2. Clitocybe. 



Sporophore densely cespitose. 3. Monadelphus. 



Lamellae sinuate or adnexed. 4. Melanoleuca. 



Lamellae waxy at maturity, translucent or watery in 

 appearance. 



Veil absent; pileus usually bright-colored. 5. Hydrocybe. 



Veil present ; pileus not bright-colored. 6. Hygrophorus. 



i. Laccaria Berk. & Br. Ann. Nat. Hist. 370. 1883 



Russuliopsis Schrot. Krypt. Fl. Schles. 3 1 : 622. 1889. 



This genus is distinguished from Clitocybe by its echinulate 

 spores and adnate gills. 



189 



