SOIL FUNGI 253 



I'". Conidiophores unbranched, or slightly 

 branched, forming a head of branches and 

 conidia: 



1"". Conidia single, not in chains: 



(a) Conidiophores unbranched, with swollen tip: 

 (a') Surface of terminal swelling definitely 



divided into hexagonal areas, Rhopalomyces. 

 Found in the soil by Beckwith. 

 (b') Surface of terminal swelling not so divided, 

 Oedocephalum. Rarely found in the soil. 



(b) Conidiophores simple, but not with swollen 

 tip, or branched: 



(a') Conidiophores unbranched, seldom divided, 



conidia adjoined at tip, one after another, but 



all remaining united into a head: 

 (a") Conidia embedded in slime, Hyalopus. 



Rarely found in soil. 

 (1)") Conidia not embedded in slime, Ceph- 



alosporium. Frequently found in the soil. 

 (I)') Conidiophores branched: 

 (a") Conidiophores tapering to a point bearing a 



head, Trichoderma (Nos. 95-96, PI. XIV). 



One of the most common groups of soil fungi. 



Very active in the decomposition of celluloses 



in the soil. Species of this organism have 



been isolated from the soil in different parts 



of the world, 

 (b") Conidiophores with three or more fine 



spines, each of which bears a head, Botryospo- 



rium. Rarely found in the soil. 

 2"". Conidia born in chains: 



(a) Conidiophores swollen at apex, Aspergillus 

 (Nos. 105-106, PI. XIV). Common in the 

 soil, represented by several species. 



(b) Conidiophores not swollen at apex: 



(a') Conidiophores branched, branches more or 

 less unequal and not radiating: 



(a") Conidia not embedded in slime, Penicillium 

 (Nos. 102-104, PI. XIV). One of the few 

 most common genera in the soil; represented 

 by many species, some of which are specifi- 

 cally soil forms. 



(b") Conidia embedded in slime, Gliocladium. 

 Isolated from the soil by Dale. 



(b') Branches of conidiophore terminal, approxi- 

 mately equal and radiating, A?nblyosporium. 

 Rarely found in the soil. 



