404 THALLOPHY TES 
Fungi Imperfecti (Imperfect Fungi) 
All Fungi in which the features characteristic of the Phycomy- 
cetes, Ascomycetes, or Basidiomycetes have not been discovered 
in their life histories are classed as imperfect Fungi. It is a 
heterogenous group, containing numerous Fungi varying widely 
in characteristics. Investigators think that most of them are 
the conidial stages of Ascomycetes in which the Ascogenous 
stage has been abandoned or has not 
| been discovered. Careful investiga- 
tions have already discovered that 
a number of Fungi which have been 
; classed as imperfect Fungi have 
ascogenous stages and are therefore 
Ascomycetes. As investigations go 
on no doubt others and probably all 
of them will be definitely classified in 
: | the other groups. 
ne 362. ae re he a ee commonly Babin the 
with Applé Blotch caused by 8FOup is the conidiospore and the 
an Imperfect Fungus. From character of this spore and the way 
Bulletin 144, Bureau of Plant j¢ is borne are the chief features upon 
Industry, U. 8. Dept. of hich the group is divided into nu- 
Agriculture ees 
merous subdivisions. 
Among them are many disease-producing forms, a large number 
of which produce serious diseases on cultivated plants. The 
Early Blight of the Potato, Leaf Blight of Cotton, Black Rot of 
the Sweet Potato, Fruit Spot of Apples, one of the Potato Scabs, 
Apple Blotch shown in Figure 362, and numerous other diseases 
are produced by these Fungi. 
Some special books on Fungi: 
HarsHBERGER, JouN W. A Text-Book of Mycology and Plant Pathology. 
Srevens, F. L. The Fungi which Cause Plant Diseases. 
Dueear, Baensamin M. Fungous Diseases of Plants. 
Masser, Grorcs. Diseases of Cultivated Plants. 
Masseg, GEorGE AND Ivy. Mildews, Rusts, and Smuts. 
