. The fungi which cause plant disease . Plant diseases; Fungi. 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
. The fungi which cause plant disease . Plant diseases; Fungi. 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 ; This fungus differs from the last in its 1 to 2 to 3-celled conidia. U. graminicola Essed causes a rice ;*'' This species differs but slightly from the two preceding. Chlamydospores smaller, conidia 1 to Please note that th
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
