Maxon, William R. <br/><br/>
Studies of tropical American ferns - no. 6. 

 - Washington  Govt. print. off.  1916. 
 - 541-608, viii p.  ill.  24 cm. 
 - Contributions from the United States National Herbarium / Smithsonian Institution. United States National Museum  v.17, pt.7 .
 - United States National Museum.  Contributions from the United States National Herbarium  v.17, pt. 7. .