Pennell, Francis W.  1886-1952. <br/><br/>
Scrophulariaceae of the central Rocky mountain states, 
by Francis W. Pennell. 
 - Washington,  Govt. print. off.,  1920. 
 - v, 313-381, vii-viii p.  25 cm. 
 - Smithsonian institution. United States National museum.  Contribuitons from the United States National herbarium.  v. 20, pt.9 .
<br/><br/> Also considered as Contribution from the New York botanical garden, no. 219. 
<br/><br/><label>LCCN: </label>agr20000972  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Scrophulariaceae--Rocky Mountains Region.
<br/><br/><label>LC Class. No.: </label>QK495.S43  / P4