Clausen, J.  <br/><br/>
Stages in evolution of plant species  (Book) 

 - New York  Cornell U.P.  1951 
 - 206p., ill.,25cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plants--Evolution
<br/><br/><label>Universal Decimal Class. No.: </label>576.12:58 CLA  / 15529