Mulford Foster collected a lot of information on plants much of which was kept on a series of card indexes and all these materials may be found in this subseries. Flyers, programs, notes, clippings, microscope slides and newsletters that provide information about plants especially bromeliads may all be found here. The notes include Mulford Foster's comments on Fosterella and Cryptanthus. Photographs form a large part of this subseries; the photograph album pages include images of several types of plant including bromeliads. There are many images of bromeliads taken in various places, such as, the field and in Foster's house and gardens, for a variety of reasons, such as, identification, record keeping or publication. The folder on Hohenbergia Salzmanii holds photographs of the plant "breathing". Most images were taken by Mulford or Racine Foster but some were taken by other individuals usually for publication or identification. Black and white prints, color prints, negatives, and slides may all be found here and are arranged alphabetically. Most of the images of bromeliads are arranged alphabetically by the plant's formal name, but a few folders at the end contain more general images of bromeliads. Images of gardens follow: gardens that are well-identified are held in separate folders arranged alphabetically. Images of non bromeliad plants are also held in this subseries. Publications include a variety of magazines and periodicals, and the negatives are images of rare books on bromeliads. The reason that some images were labelled "sample photographs" is unknown.