Cullen, J. <br/><br/>
The identification of flowering plant families :  including a key to those native and cultivated in north temperate regions / 
J. Cullen. 
 - 4th ed., completely rev. and edited. 
 - Cambridge, UK :  Cambridge University Press ,  c1997. 
 - xii, 215 p. :  ill. ;  20 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>0521585503 (pbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Angiosperms--Identification.<br/>Flowers.