Families and genera of Spermatophytes recognized by the Agricultural Research Service / 
Charles R. Gunn ... [ et al.] 
 - 500 p. :  il. ;  28 cm. 
 - Technical Bulletin ;  1796 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>ESPERMATOFITAS
<br/><br/><label>Dewey Class. No.: </label>589.092  / F35 1992