179 



The pycnidia of this species approach those of a Cytospora. 

 They are not only lobed within and pseudolocellate, but are 

 often clustered several together in one pustule with the ostioles 

 emergent in a common disc. In fact, it stands in the same 

 relation to a typical Phomopsis as Chorostate does to the other 

 sections of Diaporthe* There is, moreover, an apparent stroma. 

 > which is sometimes greenish, but this seems to be part of the 



altered cortex, for the green tinge is due to plastids. The 

 pycnidia are deeply seated, and in growing to the surface push 

 up a large quantity of the cortex before them. 



All the specimens in the Herbarium under the synonyms given 

 above belong to the same species: they all have the same spores 

 and sporophores, and differ merely in age. In the specimen of 

 Cytospora Robiniae, ex herb. Schweinitz, which is old and cxo- 

 lete, the fusoid spores are very few, but they are accompanied by 

 a few filiform hooked bodies exactly like Pltomopsis B-spores, 

 , measuring about 18-20 x 1 p. These were seen and sketched 



by Berkeley. There are also specimens of some of the other 

 species of Cytospora upon Robinia: of these C. parva, Berk. & 

 Curt. (no. 3424!) is smaller and otherwise different, having 

 broader and more u tip-cat "-like spores, approaching those of 

 Phomopsis stictica, Trav., and C. coccinea, Ft., is quite different. 



It is very possible that this C. parva is equal to Phoma 

 abnormis, Sacc, and both are equivalent to Phomopsis Pseuda- 

 caciae, Trav., which 'has " tip-cat "-like spores. The latter 

 species, which belongs to Diaporthe fasciculata, Nits., of the 

 section Euporthe, is smaller than P. oncostoma, and is found 

 on petioles as well as on twigs. . 



The conclusion is that there are two species of Phomopsis 

 occurring on Robinia — branches, twigs, and petioles in the one 

 case, branches and twigs in the other — the one tending to be 

 unilocular, and belonging to D. fasciculata, the other to be 

 plurilocular and belonging to D. oncostoma. This confirms the 

 result arrived at by the study of the species in the former paper, 

 viz., that the pycnidia of true Diaporthe, Trav. belong to typical 

 Phomopsis, while tho« k belonging to Chorostate, Trav. tend 



rather to resemble, more or less, Fusicoccum or Cytospora. 

 Further examples of the latter case are seen in Phomopsis 

 quercina and P. fibrosa, belonging: respectively to D. (Choro- 

 state) leiphaemia and D. (Chorostate) fibrosa. The former of 

 these has various forms of pycnidia and spores, ranging from 

 true Phomopsis to true Fusicoccum-. This result might be made 

 a fair ground for argument in favour of the generic separation 



of Chorostate, as adopted by Traverso. Vide infra, no. 433. 





423. 



* 



TJ 



H 



all from 

 y's only 



reason for lumping them together was that he recognised in 

 them a common character which we know now to be that distinc- 

 tive of Phomopsis. 



These three are — (1) Phomopsis viridarii, Grove, in Kew Bull. 

 1917, no. 409t>, on twigs of Magnolia tripetaJa, p. 67; (2) no. 



