CHYTRIDIALES 325 



Sporangium with more than one discharge papilla 



Sporangium truncate, with two broad, oppositely placed apical 

 discharge papillae; apophysis slightly developed, rhizoid 

 somewhat broad, unbranched or branched . . P. biporosum, p. 334 

 Sporangium somewhat spherical ellipsoidal or urceolate with one 

 to thirty-five discharge papillae 

 Endobiotic apophysis unbranched, somewhat spherical or sac- 

 cate; parasitic 

 Zoospores 3-4 \l in diameter, with one or two oil drops; para- 

 sitic on ascospores P. lippsii, p. 335 



Zoospores 3-7 \i in diameter, with a single globule; parasitic 

 on pollen grains, Synchytrium resting sporangia, marine 

 algae or nematodes 

 Parasitic on pine pollen 



Resting spore with numerous stout, blunt papillae 



P. papillatum, p. 336 



Resting spore smooth-walled P. palustre, p. 336 



Parasitic on eggs, cysts, and adults of nematodes; resting 



spore smooth-walled P. nematodeae, p. 337 



Parasitic on resting sporangia of Synchytrium endobioticum; 



resting spore wall roughened P. synchytrii, p. 337 



Parasitic on the marine alga Cladophora japonica 



P. marinum, p. 337 

 Endobiotic apophysis branched or unbranched and taproot- 

 like; saprophytic or parasitic 

 Apophysis branched ; saprophytic on animal substrata 



P. kniepii, p. 338 

 Apophysis taproot-like, sometimes branched; on pollen 



P. africanum, p. 338 

 Sporangium wall ornamented 



Sporangium wall covered with long delicate flexible branching hairs 



P. chaetiferum, p. 339 

 Sporangium wall dentigerate 

 Teeth bipartite, scattered over entire surface of sporangium 



P. aureliae, p. 339 

 Teeth plain or bipartite 



A single apical spine always present, with up to four whorls 



of teeth on body of sporangium P. mucronatum, p. 340 



No apical spine present, teeth confined to apex of sporangium 

 Teeth plain (not bipartite), four in number . . P. plaiucorne, p. 341 

 Teeth bipartite, variable in number or ten in a six-four 

 arrangement 

 Teeth forming a single whorl around the discharge papilla 



