118 



PHYCOMYCETEAE 



Fig. 39. Saprolesniales, Family Rhipidiaceae. (A-D) Rhipidium americanum 

 Thaxt. (A) Habit sketch. (B) Detail of branch bearing zoosporangia. (C) Discharge 

 of zoospores. (D) Two oogones, each with a mature oospore. (E-G) Araiospora 

 pulchra Thaxt. (E) Portion of plant bearing an oogone and zoosporangia of both 

 types (F) Oogones and antherids. (G) Ordinary and spiny zoosporangia. (After 

 Thaxter: Botan. Gaz., 21(6):317-331. Univ. Chicago Press.) 



