IOWA ACADEMY OF SCIENCES. 209 



Quercus rubra L. Red oak. The most abundant of the black 

 oak species. Found on upland in connection with the hickory 

 and bur oak. 



Quercus coccinea Var. tinctoria Wang. Black oak. Not com- 

 mon. 



SALICACE^. 



Salix nigra Marsh. Black willow. Very abundant along 

 banks of the streams. 



Salix discolor Muhl. Pussy willow. 



Fopulus tremuloides Michx. American aspen. Very common 

 on low damp soil. This is one of the most conspicuous trees 

 on the upland, growing along the edges of wet places. 



Fopulus monilifera Ait. Cottonwood. Common on rich soils 

 along the banks of streams and in low places. 



GYMNOSPERM^. 



CONIFER.E. 



Juniperus virginiana Li. Red cedar. Quite common, found 

 growing among the trees on the upland. They are transplanted 

 before the trees become any size. 



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