ORDER SPHAEROPSIDALES 



579 



malorum Pk. causes twig cankers on apple and quince and the black rot of 

 the fruits. Its perfect stage is Physalospora. The imperfect form genus is 

 broken up by the more recent authors into several form genera. The name 

 Sphaeropsis having been first applied to the perfect stage of an Asco- 

 mycete should, according to Petrak and Sydow, be replaced by Haplo- 

 sporella. Some of the species usually included here they transfer to 

 Botryodiplodia, including among those so transferred S. malorum. Conio- 

 thyrium has smaller pycnidia and very much smaller conidia which emerge 

 from the ostiole in a black cirrhus. C. fuckelii Sacc, the cause of the cane 

 blight of various species of Rubus, has as its perfect stage Leptosphaeria 

 coniothyrium (Fckl.) Sacc, in the Sphaeriales. Ascochyta (Hyalodidymae) 







Fig. 192. Sphaeropsidales, Family Sphaeropsidaceae. (A) Ceuthospora abietina 

 Delacr.; section through stroma with several pycnidial cavities with one common 

 ostiole. (B, C) Septoria aesculi (Lib.) West. (B) Section through pycnidium. (Cj 

 Spores. (E-F) Phomopsis citri Fawcett. (E) Section through pycnidium. (F) Portion 

 of wall of pycnidium showing pycnospores and the long, slender, curved stylospores. 

 (D) Family Leptostromataceae. Leptothyrium acerimim (Kunze) Corda; section 

 through pycnidium. (A, after Delacroix: Bull. soc. mycol. France, 6(4);181-184. B-C, 

 after Briosi and Cavara: Fascicle V, No. 120. E-F, after Fawcett: Phytopathology, 

 2(3) -.109-113. D, after Briosi and Cavara: Fascicle II, No. 40.) 



