Lawrence, George Hill Mathewson,  1910- <br/><br/>
An introduction to plant taxonomy / 
George H. M. Lawrence; illustrations by Marion Ruff Sheehan 
 - New York :  MacMillan,  1955 
 - 179 p. :  ill. ;  22 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Botany North America --Classification