226 REPORT OF THE DEPARTMENT OF BOTANY OF THE 
at the septum. These septate spores are larger than the others — 
commonly 3.5 x 12-14 4. Frequently, the non-septate spores pre- 
dominate to such an extent that the fungus might readily pass for 
a species of Phyllosticta, but undoubtedly it is properly referable 
to the genus Ascochyta. It may be an undescribed species. ds- 
cochyta medicagims Bres.®® on Medicago lupulina has larger spores 
and pycnidia; so has Ascochyta pisi Lib. which is reported as occur- 
ring on alfalfa in Denmark.®’ Ascochyta medicagims Fuckel,** 
found on living leaves of Medicago sativa and M. falcata in Ger- 
many, is a synonym of Phyllosticta medicagimis (Fckl.) Sacc.® the 
spores of which are described as very small and the pycnidia black. 
It is unlikely to be Ascochyta caulicola Laub.’? which attacks the 
stems and petioles of Melilotus alba. 
When the Ascochyta was first discovered (October, 1907) it was 
thought to be identical with the Diplodina medicaginis Oud. 
previously found on dead alfalfa stems in early spring (see page 
237); but after careful comparison of the two fungi we have 
reached the conclusion that they are distinct. The spores of the 
two species are strikingly alike except in one respect, viz., the spores 
of D. medicaginis are commonly biguttulate while those of the As- 
cochyta are rarely so. The pycnidia of D. medicaginis are some- 
what larger than those of the Ascochyta and black, while those of 
c\scochyta are light brown. ‘So far as observed neither the Diplo- 
dina nor the Ascochyta attack living alfalfa stems. 
There is no reason to believe that the Ascochyta leaf spot will be- 
come a troublesome disease. 
STAGONOSPORA LEAF SPOT. 
(Stagonospora carpathica Bauml. ?) 
While examining one of the Station alfalfa fields June 9, 1908, 
the writers found a leaf spot disease not previously observed. The 
following day the same disease was found in another field near 
Geneva. *In neither case was the disease sufficiently abundant to 
cause appreciable damage, yet affected leaves were so common that 
several hundred specimens were collected in a short time. 
* Bresadola (7). 
“ Rostrup (84), (85). 
* Fuckel (34). 
ww Saccargo. (S014 242). 
“Saccardo. (OG; 185330). 
