136 
XV.—SPECIES PLACED BY SACCARDO IN THE 
GENUS PHOMA. 
Part ITI. 
W. B. GRovE. 
The present communication is a continuation of those which 
have appeared in the Kew Bulletin for 1919, pp. 177-201 and 
425-445. The three parts together form a revision of most of 
those doubtful species of Phoma, of which specimens are preserved 
at Kew, and which were included in Saccardo’s Sylloge, vol. III. 
But there are two limitations of its scope: (1) those previously 
treated of in my “ British Species of Phomopsis”’ (Kew Bulletin, 
1917, pp. 49-73) are not again referred to, and (2) none are 
mentioned except those of which good and, so far as possible, 
authentic examples were available. The absence of some which 
‘one might have expected to be included is due, in nearly every 
case, to the poverty of the specimens at hand, which might 
have led to erroneous conclusions. Moreover, the enquiry has 
not as yet been extended to those species which are contained 
in the later volumes of Saccardo, although some of them are 
equally in need of revision. 
It is satisfactory that, by this means and by the labours of 
von Hoéhnel and other workers elsewhere, the genus Phoma has 
now been relieved of many species referred to it by the older 
mycologists, who regarded it as a convenient receptacle for 
doubtful forms. The genus Macrophoma, too, has almost dis- 
appeared. 
It becomes plain, after examining a series of so-called species 
of Phoma like these, that there is a great possibility, and in 
many cases a certainty, of recognising the genus to which they 
really belong, even though the spores may be very young and 
so may not show the nominal generic character. The genera 
Phoma, Phomopsis, Ascochyta, Diplodina, Diplodia, etc. (not to 
mention Sphaeropsis, Coniothyrium and the Leptostromaceae) all 
have, even when imperfectly developed, certain distinctive traits 
which are suggestive, if not decisive. These traits should 
encourage a more persistent search, and, as many instances 
have shown, such a search will often be at length rewarded by 
the discovery of a few more fully-formed spores scattered among 
the rest. Apart from this, it is now beginning to be recognised 
that the nature of the pycnidium, and especially its texture, is 
in many cases as characteristic as any other feature of the 
Coelomycetes 
In what follows all figures, except where otherwise described, 
are X 600. 
