Clausen, Jens. <br/><br/>
Experimental studies on the nature of species :  I. effect of varied environments on Western North American plants / 
Jens Clausen, David D. Keck, William M. Hiesey. 
 - Washington, D.C.,   Carnegie Institution of Washington Publication,  1940.. 
 - v. :   ill. ;   25 cm. 
 - Carnegie Institution of Washington Publication   No. 520 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plant ecology<br/>Heredity
<br/><br/><label>LC Class. No.: </label>SPE-B 05826