Powell, A. Michael. <br/><br/>
Trees & shrubs of Trans-Pecos Texas :  including Big Bend and Guadalupe Mountains National Parks / 
by A. Michael Powell. 
 - Big Bend National Park, Tex. :  Big Bend Natural History Association,  c1988. 
 - 536 p. :  ill. ;  23 cm. 
<br/><br/> Includes index. 
<br/><br/>Bibliography: p. 487-491. 
<br/><br/><label>ISBN: </label>0912001143 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Trees--Texas.<br/>Shrubs--Texas.