Hansell, Dorothy E., 1953, 1967

This series contains correspondence documenting the professional and personal exchanges of Drs. Otto and Isa Degener. Topics include their collaborative research on Hawaiian flora, as well as their conservation efforts opposing deforestation, environmental destruction, and the introduction of invasive species. The correspondence also covers their activities related to selling and publishing books, matters concerning their rental properties, reminiscences about early twentieth-century Hawaii, and reflections on various individuals and issues. The series contains obituary tributes written by Dr. Otto Degener for fellow botanists, many of which were published in Flora Hawaiiensis and are included here when available.

This series also includes extensive correspondence with botanists based in Germany, Japan, Hawaii, and the United States, as well as exchanges with staff from botanical institutions including the New York Botanical Garden, the Bishop Museum, the Berlin Botanical Garden, the Hunt Institute for Botanical Documentation, and various universities.

In addition to botanical and institutional correspondence, this series contains letters from friends, neighbors, and colleagues. Family correspondence is organized separately in the Degener family file. Prominent correspondents include Ross Bean, Nathaniel Lord Britton, Everett Brumaghim, Bill Bryan, Ray Fosberg, Charles Gunn, Bill Hatheway, Hans Hormann, Charles Long, the Moldenke family, Elmer Merrill, George Munro, Noah Pekelo, Peter Raven, Earl Sherff, Albert Charles Smith, Sy Sohmer, William Steere, Benjamin Stone, Rene Sylva, Ray E. Torrey, Herbert Whetzel, Henry Wiebke, and Keith Wooliams.