IMPERFECT FUNGI 239 
producing whitish or discolored spots, and eventually 
developing small perithecia-like structures (pycnidia) 
containing conidia. Species of Phyllosticta are common 
on leaves of Virginia creeper, wild grape, cottonwood, 
willow, pansy, peach, apple, wild cherry, elm, etc., while 
species of Septoria are to be found on leaves of box-elder, 
aster, thistle, evening primrose, wild lettuce, plum, 
elder, ete. 
412. The Black-dot Fungi (Order MELANCONIALEs) 
differ from the preceding mainly in the absence of a 
distinct perithecium, the spores developing beneath the 
epidermis of the host and bursting through so as to form 
WO 
Fie. 115.—Septoria. Fie. 116.— Fig. 117.,—Cercospora. 
loeosporium. : 
small dark-colored or black dots (acervuli). Species of 
Gloeosporium and Melanconium are common on leaves, 
fruits, and twigs. 
413. In the Molds (Order MoniLiauzs) the conidia- 
bearing threads emerge through the stomata of the host, 
or grow out through the outer decaying tissues, forming 
moldy patches or masses. Here are many common 
parasites (e.g. species of Ramularia, Cercospora, Fusi- 
cladium) and saprophytes (Monilia, Botrytis, etc.), some 
of which are both parasitic and saprophytic. 
Laboratory Studies. Although the Imperfect Fungi are 
quite too difficult for the beginner to do much with, it is well 
that he should become somewhat familiar with their general 
appearance; accordingly a few studies are suggested. 
