General Key to Families 



A. Hyphal filaments 1-cclIed, very rarely septate, 



largely aquatic; propagation by zoospores, co- 

 nidia or both; sex-cells often present, producing 

 resting-spores 



B. Hyphal filaments septate, rarely aquatic; propa- 



gation by conidia; sex-cells usually absent 



1. Spores borne in asci or on tru(:; basidia 



a. Spores borne in asci 



b. Spores borne on true basidia 



2. Asci or basidia lacking 



a. Spores stalked, sessile or internal but not 



borne on conidiophores, producing a pro- 

 mycelium on germination; conidia often 

 present in the form of aecia or uredia 



b. Conidia alone present, borne on conidiophores 



of various form, often contained in pycnidia 



Phycomycetes p. 23, 30 



Ascomycetes p. 24, 42 

 Basidiomycetes p. 28, 157 



Promycetes p. 28, 147 

 Deuteromycetes p. 29, 175 



PHYCOMYCETES 



A. Mycelium lacking or scanty and consisting of a 



few delicate hyphae; propagation by amoeboid 

 cells and spores or by sporangia and zoospores; 

 sex-cells rare 



1. Mycelium lacking 



a. Cells typically amoeboid 



b. Cells not amoeboid 



(1) Sporangia separate or grouped, but with- 



out a soral membrane 



(2) Sporangia typically enclosed in a soral 



membrane 



2. Mycelium scanty, hyphae typically few and 



delicate 



B. Mycelium present, typically well-developed and 



ramose; propagation by zoospores or conidia; 

 sex-cells usually present 

 1. Typically aquatic fungi propagating by zoo- 

 spores 

 a. Mycelium mostly well-developed 



(1) Antheridial tube touching or penetrating 



the oogone 



(2) Antherids producing ciliate antherozoids 



(a) Hyphae much branched; reproduction 



by isogametes 



(b) Hyphae mostly simple; reproduction by 



heterogametes 



23 



Plasmodiophoraceae p. 30 



Olpidiaceae p. 30 

 Synchytriaceae p. 31 

 Chytridiaceae p. 32 



Saprolegniaceae p. 38 



Blastocladiaceae p. 40 

 Monoblepharidaceae p. 41 



