362 A TEXTBOOK OF GENERAL BOTANY 
rust (Puccinia graminis). In this species the eciospores are 
found on barberry leaves (Fig. 874), and the urediniospores and 

——. KF ¢ 

Fig. 892. Three forms of lichens 
Above, Usnea barbata, a branched epiphytic form; lower left, Haematomma 
puniceum, a crustaceous form; lower right, Cladonia Jurcata, an erect terrestrial 
form. (x 1) 
the teliospores on wheat (Figs. 373, 377). As the basidiospores 
of Puccinia graminis do not infect wheat but only infect the 
barberry bush, this disease can be very largely controlled by 
ri 
ae 
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