Clausen, Jens Christian <br/><br/>
Stages in the evolution of plant species 

 - New York  Hafner Publishing Company  1962 
 - 206p.  24cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plamts
<br/><br/><label>LC Class. No.: </label>QK980.C65