97. POPULUS HETEROPHYLLA, L. 



Swamp Poplar, Downy Poplar, River CottonwoocL 



TRANSVERSE SECTION. 



RADIAL SECTION. 



TANGENTIAL SECTION. 



Suinpf-Pappel. eFz. Peuplier marecageaux. Sp. Alamo pantonosc 



Publish^ and Sections made by Romeyn B. Hough, B. A., Lowvffle, H. Y., U. S. A. 



