Stebbins, G. Ledyard  1906- <br/><br/>
Flowering plants :  evolution above the species level / 
G. Ledyard Stebbins 
 - Cambridge, Mass. :  Belknap Press of Harvard University Press,  1974 
 - xviii, 399 p. :  ill. ;  24 cm. 
<br/><br/>Includes bibliographical references (p. 356-380) and index 
<br/><br/><label>ISBN: </label>0674306856 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Plants--Evolution<br/>Angiosperms--Evolution