Thankfully before tossing in the trash people have donated historic slide collections to the library. Although these range in quality and degree of deterioration, they still offer pieces of historic puzzles. For example an image that has faded in color may still tell us proportions and markings of an historic Iris that may have no good photos extant. With the aid of these historic remnants identities of some irises with questioned identities may be confirmed. Confirmation is really always impossible to know for sure but these images provide evidence to support identification. These time worn images may be included in the reference section of a given iris' cultivar page and may support the validity of later images taken in the present.
List of Collections:
For more information on historic Irises visit the Historic Iris Preservation Society at http://www.historiciris.org/
-- BobPries - 25 Jun 2019