POLYGONACEiE 295 



wheat will grow well on poor soil — a soil that will not support 

 true cereals. Therefore, it may be used as a green-manure 

 crop. 



References 



Morse, J. F.: The New Rhubarb Culture. Orange Judd Co., 191 2. 

 Stevens, N. E.: The Morphology of the Seed of Buckwheat. Bot. Gaz., 



53: S9-66, 1912. 

 Observations on Heterostylous Plants. Bot. Gaz., 53: 277-308, 191 2. 

 TsuTSUMi, Ochimura: Studies on the Buckwheat. Bot. Mag. (Tokyo), 



8: 288-291; 417-421, 1894. 

 Williams, F. N.: Primary Characters in the Species of Rheum, 29: 292-295, 



1891. 



