The index cards appear to be bibliographies of literature pertaining mostly to ferns and algae and were probably typed or written by both Franklyn D. Ott and Aleta Jo Petrik-Ott. The index cards with book titles are arranged by author, by subject, and also by year or time period. The book titles and authors represented on the index cards range in date from the 1600s-1990s. There are also general subject sections with reference information written on cards and other resources besides book titles. In the general subject files, there are also some miscellaneous items such as a small notebook, photographs, and clippings. There are several boxes of index cards that were not yet interfiled by the Otts into the larger sequences.