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IOWA ACADEMY OP. SCIENCE 
Fig. 1. Leaves. (See p. 81.) 
Quercus palustris DuRoi. The two lobed leaves. 
Quercus imhricaria Michx. The three entire leaves. 
Fig. 2. Leaves. (See p. 81.) 
Quercus imhricaria x palustris. Three leaves showing variation in form. 
