Laetsch, Watson M. <br/><br/>
Plants  basic concepts in botany 
Watson M. Laetsch. 
 - Boston  Little Brown & Co.  1979. 
 - 510 p. : ill. ; 23 cm. 
<br/><br/> Includes index. 
<br/><br/>p.483-489. 
<br/><br/><label>ISBN: </label>0316511862 
<br/><br/><label>LCCN: </label>78-64497 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Botany