232 



CLASS ASCOMYCETEAE 



bright-colored. The ascospores are three- to four-celled. CMorocihoria 

 aeruginosa (Oed.) Seaver occurs on wood and stains it green. Tricho- 

 scyphella {Dasyscypha of some authors) forms mostly short-stalked apo- 

 thecia on the bark or cones of conifers. T. willkommii (Hart.) Nannf. is 

 a serious canker-producing parasite of Larix. 



Family Sclerotiniaceae. Mostly parasitic but capable of prolonged 

 growth as saprophytes. Apothecia fleshy, stipitate, mostly cupulate, 

 funnel-formed or saucer-shaped, in one genus resembling Verpa; usually 

 some shade of brown ; arising from a definite sclerotium or from a stroma- 

 tized portion of the substratum. Asci inoperculate, mostly eight-spored, 

 ascospores ellipsoidal, often flattened on one side, usually hyaline, uni- 

 cellular and smooth. Spermatia globose to slightly oval, conidial forms 

 various, in most genera lacking (Whetzel, 1945). As in the preceding 

 family the main portion of the excipulum consists of entangled hyphae, 

 only at the outer surface being reduced to short, somewhat pseudo- 

 parenchymatous cells. The stroma may be a free tuberoid sclerotium 

 as in the genus Sclerotinia or may be formed in the tissues of the host 

 which are digested and replaced by the fungus hyphae, e.g., Cihorinia, 

 Ciboria, Monilinia, or may be plano-convex and attached to the host, 

 Botryotinia, Septotinia, etc., or may be indeterminate or of the substratal 

 type, Lamhertella, Rutstroemia, etc. In all, Whetzel recognized fifteen 

 genera including over ninety species. Many of them were formerly in- 

 cluded in the genus Sclerotinia. Among the serious pathogens may be 

 mentioned Sclerotinia sclerotiorum (Lib.) de Bary, Monilinia fructicola 

 (Winter) Honey {Sclerotinia fructicola Rehm) , the cause of the brown rot 

 of stone fruits in America. Its conidial stage is of the Monilia type. 

 Botryotinia fuckeliana (de Bary) Whetzel is the cause of a serious disease 

 of the grape vine in Europe. Its conidial stage is a Botrytis of the B. 



B 



Fig. 80. Pezizales, Family Sclerotiniaceae. Scleroiinin sclerotiorum (Lib.) de Bary. 

 (A) Apothecia growing from sclerotium. (B) Magnified section of sclerotium. (After 

 Brefeld: Unter. Geaammt. Mykol, 4(7):112-121.) 



