418 CONNECTICUT EXPERIMENT STATION REPORT, 1912. 



Besides these, there is a somewhat similar appearing fungus 

 recently described, by H. & P. Sydow (Ann. Myc. 10, p. 82) 

 on Quercus from Colorado, as Calopactis singularis. It is a 

 semi-parasitic species, apparently, whose generic position is some- 

 what doubtful, as the asco-stage has not been found. It has 

 been known in this country for some time, and by some botanists 

 has been placed under Endothia gyrosa, since the fruiting pus- 

 tules and the Cytospora spores of the two are very similar. 

 However, the fruiting pustules are larger, deeper crimson in 

 color, and in maturity more powdery. We have it in culture 

 from a specimen recently sent by Bethel from Colorado, and 

 while it grows something like E. gyrosa, it does not form any 

 distinct conidial fruiting pustules on media tried so far, and in 

 manner of growth and color of mycelium resembles more nearly 

 the cultures of E. radicalis. 



Of the species mentioned, we need to consider in connection 

 with the blight fungus only Endothia gyrosa, already discussed 

 somewhat, and Endothia radicalis, since these three in their 

 Cytospora stage are so similar in appearance that they cannot 

 be distinguished by the naked eye, and all have at least the oak 

 as a common host. As E. radicalis is most sharply set off from 

 the other two, we will discuss it first. 



Endothia radicalis. While the fruiting pustules of this species 

 are not different from the other two, when we examine the asco- 

 stage under the microscope it is very easily distinguished by 

 the much narrower spores. These ascospores vary from linear 

 to linear-oblong, are occasionally slightly curved, are apparently 

 single-celled, though possibly they may in some cases develop 

 an indistinct septum, and are 6-10 /M, rarely 12 /*, . long by 

 1-2 /A wide. We have never seen spores which grade into those 

 of the other two species described here, so it is apparently quite 

 a distinct species. See Plate XXVIII a, d. 



It seems to be largely southern, having been found in its 

 asco-stage in Louisiana, Mississippi, Georgia, Alabama, Florida 

 and North and South Carolina. However, there are specimens 

 in various herbaria from much further north, xshowing only the 

 conidial stage, that apparently belong to this species. One speci- 

 men found in Connecticut has been under observation on roots 

 of an oak tree for over a year, and though in a vigorous grow- 

 ing condition, has made no attempt to form the asco-stage. 



