118 



Spotted Spurge. 



Three-seeded 



Mercury. 



Slippery or Red 

 Elm. 



White Elm, 



Hackberry. 

 Red Mulberry. 



Wood-Nettle. 

 Clear-weed. 

 Hemp. 

 Hop. 



Button-wood or 

 Sycamore. 



Butternut. 



Black Walnut. 



AGRICULTURAL COLLEGE. [No. 17. 



Euphorbia maculata, L. 



Ames ; Charles City. 



Euphorbia hypericifolia, L. 



Ames. 

 Euphorbia marginata, Pursh. ( ? ) 



Grinnell. 



Euphorbia corollata, L. 



Ames ; Grinnell ; Charles City ; Burlington. 



Acaljpha Virginica, L. 



Ames ; Charles City. 



TJRTICACE.E. 



Ulmus fulva, Michx. 



Ames ; Charles City ; Fayette ; Burlington. 



Ulmus Americana, L. 



Ames ; Charles City ; Fayette ; Burlington. 



Celtis occidentalis, L. 



Ames. 



Morus rubra, L. 



Ames. 



Laportea Canadensis, Gaudich. 



Ames ; Grinnell. 



Pilea pumila, Gray. 



Ames. 



Cannabis saliva, L. 



Ames. Escaped to road-sides and fence-rows. 



Humulus Lupulus, L. 



Ames. Found abundantly in timber land. Certainly indige- 

 nous. Also at Burlington. 



PLATANACE^E, 



Platanus occidentalis, L. 



Ames ; Fayette ; Burlington. 



JUGLANDACE.E. 



Juglans cinerea, L. 



Ames ; Fayette ; Burlington. 



Juglans nigra, L. 



Ames ; Fayette ; Burlington. 



