The Paleobotany Collection is comprised of approximately 1,100 specimens and over 2,800 elements. Virtually all of these specimens were acquired by the College during the 19th century, often at the behest of Charles Upham Shepard or Edward and Charles Hitchcock. Fossil forms include carbon films, compressions/impressions, and perimineralized specimens, and structures include leaves, bark, root traces, wood, seeds and cones.
Most major groups of vascular and seed plants are represented. Approximately one third of the collection is from the Carboniferous period, but the holdings include material dating back as far as the Ordovician of Wisconsin and as recently as the late Pleistocene of Hadley, Massachusetts. The flora of Massachusetts, Rhode Island, New York, Pennsylvania, Nova Scotia, New Brunswick, England, and Germany are particularly well represented; other localities of interest include Pennsylvanian age Mazon Creek nodules of Illinois and Florrisant flowering plants from the Eocene of Colorado.
Also present in the collection is the probable type specimen of Pachyphyllum simile from Sunderland, Massachusetts.