IOWA ACADEMY OF SCIENCES. 203 



Qiiercus Miihlenhergii. Chesthiut Oak. 



Not common. Found on steep, rocky hillsides. 

 Qiiercus macrocarpa Michx. Bur Oak. 

 Very common. Found everywhere, but more abun- 

 dant on the upland. 



Quercus j)alustris Du Roi. Spanish Oak. 



Frequent. 

 Quercus rubra Linn. Red Oak. 



Common. 

 Quercus coccinea Wan^. Scarlet Oak. 



Quite common on upland. 

 Quercus coccinea Var. tincforia Gray. Black Oak. Jack 

 Oak. Common on upland. 

 Salicace^. 



Salix trisfis. Dwarf Willow. Cray Willow. 



Somewhat rare. Found on upland bordering thickets. 

 Salix hiimilis Marsh. Prairie Willow. 



Common on uplands. 

 Salix discolor Muhl. Pussy Willow. 



Rare; wet places. 

 Salix longifolia Muhl. Sand-bar Willow. 



Common in low, wet places and on sandbars. 

 Salix nigra Marsh. Black Willow. 



Very common along the banks of streams. 

 Popidns tremuloides Michx. American Aspen. Quaking 



Asp. Rare. Upland. 

 Populus monilifera Ait. Cottonwood. 



Very common along streams, the largest trees grow- 

 ing on very low ground near the water. This tree 

 makes very rapid growth. Trees become large 

 enough for lumber in thirty to forty years. 

 Monocotyledones. 



LlLIACE^. 



Sniilax hispida Muhl. Greenbrier. 

 Quite common in rich woods. 



