ECOLOGIC AND MORPHOLOGIC STUDY OF THE 

 CLOVERS (TRIFOLIUM). 



By JOHN W. HARSHBERGER. 

 (Read April 21, 1922.) 



This study of the clovers was begun in 1907 and has been pursued 

 intermittently ever since. Sufficient data has accumulated to warrant 

 its assemblage for publication. The material for investigation was 

 gathered in the open for all of our common species, numbering about 

 six, and the remainder was raised from seeds planted in pots in the 

 greenhouse. After considerable correspondence, which was seven 

 years before the outbreak of the world war, seeds were obtained from 

 Ames (Iowa), Amsterdam (Holland), Berlin (Germany), Besancon 

 (France), BurHngton (Vermont), Cambridge (England), Copen- 

 hagen (Denmark), Dijon (France), Dublin (Ireland), Hamburg 

 (Germany), Innsbruck (Austria), Kew (England), Knoxville (Ten- 

 nessee), Lincoln (Nebraska), Northampton (Massachusetts), Rome 

 (Italy), St. Louis (Missouri), St. Petersburg ^^ Petrograd (Russia), 

 Tiflis (Persia), Tucson (Arizona), Vienna (Austria), Washington 

 (District of Columbia). The seeds from Washington, D. C, were 

 obtained from agrostologists connected with the United States De- 

 partment of Agriculture and from the Bureau of Foreign Seed and 

 Plant Introduction. Some seeds were purchased from dealers in 

 New York and Philadelphia. The trial sowings of these seeds 

 showed that most of them readily germinated, but some of them were 

 refractory, or failed to sprout entirely. The seedlings and young 

 plants intended for histologic investigation were fixed in chromacetic 

 acid and finally put into 50 per cent, alcohol for preservation. The 

 growing plants were used for experimentation on their leaf move- 

 ments. 



Number of Seeds in the Pods. 



Some of the material received from botanical gardens had not been 

 hulled and it was thought worth while to determine how many seeds 



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