214 THE FUNGI WHICH CAUSE PLANT DISEASE 



is not known but which is placed in this genus on account of the 

 similarity of its conidial stage with that of the other species. 



U. virens (Cke.) Tak. Ascigerous stage unknown, sclerotia spher- 

 ical, about 5 mm. in diameter; conidia spherical, at first smooth- 

 walled, hyaline, at maturity 

 echinulate and olive green, 

 4-6 M- 



The short thick walled 



fr ^^ hyphae of the interior of the 



sclerotium are closely in- 



_,,.„,-. -. . • terwoven to a false tissue, 



liG. 153. — U. virens; a, spores germinated m . ' 



water; b, germinated in bouillon. After toward the periphery they 



become parallel and are di- 

 rected radially. Here a yellow layer is produced and spores are 

 formed laterally on the hyphae. When mature the spores are in 

 mass dark olive-green and form an outer green layer on the 

 sclerotium. The spores germinate in water, producing a vegeta- 

 tive mycelium which bears secondary spores and somewhat re- 

 sembles the myceHum of the Ustilagioales.^^^ Successful inocula- 

 tions have not been made. 



Ustilaginoidella Essed (p. 199) 



This is a genus -erected by Essed "*^ to receive the species 

 U. musaeperda, which he regards as the cause of the "Panama 

 disease" of bananas, at least as it occurs in Suriname. 



Sclerotia similar to those of Ustilaginoidea are found; chlamyd- 

 ospores and conidia obtain, among the latter are some of marked 

 Fusarium type; others are in pycnidia. 



U. oedipigera Essed is also described by Essed '"* as the cause 

 of another less important banana disease in Suriname and Colum- 

 bia; a disease accompanied by h3T)ertrophy of the base of the 

 stem and leading to the common name "bigie footoe." This 

 fungus differs from the last in its 1 to 2 to 3-celled conidia. 



U. graminicola Essed causes a rice disease."*'' This species 

 differs but slightly from the two preceding. Chlamydospores 

 smaller, conidia 1 to 5-celled. 



