PLATE 49 



A. Cross-section of black Indian hemp {Apocynum cannabinum, L.). 



1. Longitudinal section of a latex tube. 



2. Cross-section of latex tube. 



3. Parenchyma. 



B, Cross-section of a part of black Indian hemp root. 



4. Cross-section of a large latex tube. 



5. Parenchyma. 



