2T6 
PLANT STUDIES 
large one, and contains a great variety of forms. All of 
them, however, produce spores in asci, but the asci are not 
always inclosed by an ascocarp. Here belong the common 
blue mould (Penicillium) found on bread, fruit, etc., in 
which stage the branching chains of conidia are very con- 
spicuous (Fig. 243) ; the truffle-fungi, upon whose subter- 
\ 
FIG. 243. Penicillium, a common mould : A, mycelium with numerous branching 
sporophores bearing conidia ; S, apex of a sporophore enlarged, showing branch- 
ing and chains of conidia. After BREFELD. 
ranean mycelia ascocarps develop which are known as 
" truffles " ; the black fungi, which form the diseases known 
as " black knot " of the plum and cherry, the " ergot " of 
rye (Fig. 244), and many black wart-like growths upon the 
bark of trees ; other forms causing " witches'-brooms " (ab- 
normal growths on various trees), "peach curl," etc., the 
cup-fungi (Figs. 245, 246), and the edible morels (Fig. 247). 
