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COLLECTION Identifier: II A-2

Alfred Rehder (1863-1949) papers, 1898-1949.


Alfred Rehder first came to the Arboretum in 1898 while on assignment for Moller’s Deutsche Gartner-Zeitungand where he held the position of Associate Editor. Intending only to stay in America for half a year he was persuaded to join the Arboretum’s staff and he remained at the Arboretum until, and beyond, his retirement in 1940. He was appointed Curator of the Arboretum’s Herbarium in 1918, became editor of the Journal of the Arnold Arboretum in 1927, and Harvard appointed him Associate Professor of Dendrology in 1934. The collection consists of biographical material, correspondence from 1898 until 1949, papers on nomenclature, a bibliographic index, and photographs of and by Rehder.


  • 1898-1949

General Physical Description note

1 box, 1 bound volume, 4-drawer file cabinet, 114 drawer card index

Terms of Access

This collection is open for research. Researchers seeking to examine archival materials are strongly encouraged to make an appointment. The Director, or an office of origin, may place restrictions on the use of some or all of its records. The extent and length of the restriction will be determined by the Director, office of origin, and the Archivist and will be enforced equally for all researchers.

Terms of Use

The copyright is held by The President and Fellows of Harvard College for the Arnold Arboretum Archives of Harvard University. The copyright on some materials in the collection may be held by the original author or the author's heirs or assigns. Researchers are responsible for obtaining written permission from the holder(s) of copyright and the Arnold Arboretum Archives prior to publishing any quotations or images from materials in this collection.

Photocopies may be made at the discretion of the Arnold Arboretum Archives staff. Permission to make photocopies does not constitute permission to reproduce or publish materials outside the bounds of the fair use guidelines.


1.5 linear feet
The majority of the collection consists of approximately two thousand letters that are indexed in the Archives’ Correspondence Database. On site the correspondence occupies a four-drawer file cabinet and is arranged alphabetically by correspondent. For correspondents with more than one letter the letters are in date order. Some of the letters are typed, others are handwritten. The quality of paper varies widely, the most fragile being the onion skin paper that was used for copies. Many of Rehder’s replies to the correspondent are included as copies on the verso of the original letters; there are also many carbon copies of his replies on onion skin paper. While most of the correspondence is in English, there is a substantial amount in German, and some in French and Spanish. There is also a bibliographic card index and a listing of Rehder’s photographs described in this guide.

Biographical note

FromAlfred Rehder, 1863-1949 by Clarence E. Kobuski, Journal of the Arnold Arboretum 30 (1) 1950

Alfred Rehder was born on September 4, 1863 at Waldenburg in Sachsen Germany, the first child of Paul Julius (1833-1917) and Thekla Rehder (1839-1897). His father was the Park Director for the Princes of Schonburg-Waldenburg, and his paternal grandfather, Jakob Heinrich Rehder had been Park Director for Prince Puckler at his park in Muskau in Upper Lusatia, Silesia. His paternal grandmother was the daughter of the head gardener on the estates of Count Bruhl in Brandenburg. After attending Gymnasium in Zwikau, Sachsen Rehder returned to his family’s home in 1881 and apprenticed to his father for three years. In 1884, Rehder began two years study at the Botanischer Garten und Botanisches Museum Berlin-Dahlem under renowned botanists, Professors August Wilhelm Eichler (1839-1887) and Paul Friedrich August Ascherson (1834-1917). He next spent a brief time with a florist in Frankfurt am Main then obtained a position with Gustav Schrefeld, who would later become his father-in-law, at the park in Muskau where his grandfather had worked. His next position was head gardener at the Grand Ducal Botanic Garden in Darmstadt and he went on to hold the same position at the Botanic Gardens in Gottingen from 1889-1895. As head gardener, Rehder instituted a complete reorganization of the gardens and began conducting research, writing about plants, and developing contacts with other botanists. Rehder left the Garden in 1895 and moved to Erfurt where he became the Associate Editor of Moller’s Deutsche Gartner-Zeitung. He published over a hundred articles during the three years he was associated with the magazine.

In “ The Making of a Botanist”, Gerhard Rehder (1908-1996), Alfred Rehder’s son, traces his family’s long association with botanical and horticultural enterprise that began in 1815 with the founding of Muskauer, the great landscape park on the border between Poland and Germany and would eventually lead to his father’s career at the Arnold Arboretum.

In 1898, at age 34, Rehder sailed for the United States to undertake dendrological studies for Moller’s Deutsche Gartner-Zeitung and to investigate fruit growing and viniculture in the northeastern United States for the German government. Wishing to pursue independent studies while pursuing his work for the German periodical, he wrote Charles Sprague Sargent (1841-1927), the first Director of the Arnold Arboretum, and arranged a six month term as a student-worker performing manual labor on the grounds for $1.00 a day. As noted in Arnoldia in 1938 “his first task was to eliminate the weeds in the then newly established shrub collection by the vigorous use of a hoe.” Sargent quickly recognized his capabilities and persuaded Rehder to become a member of his staff. Almost immediately Rehder began contributing all the dendrological articles for Liberty Hyde Bailey’s Cyclopedia of American Horticulture, a commitment that lasted several years.

In 1901, Sargent assigned him the enormous task of assembling the bibliographic data required in compiling The Bradley bibliography: a guide to the literature of the woody plants of the world published before the beginning of the twentieth century. The research and publication of the bibliography was funded by Abby A. Bradley as a memorial to her father, William Lambert Bradley (1826-1894) an innovator in the field of chemical fertilizers.

Rehder spent the next seventeen years compiling detailed information for the over 100,000 titles that would eventually appear in a five-volume, 3,895-page publication that brought together references to the literature of woody plants published in all “books, pamphlets, and articles in periodicals and other serials in all languages up until the end of 1900.” Rehder next contributed extensive taxonomic work to Plantae Wilsonianae; an enumeration of the woody plants collected in western China for the Arnold Arboretum of Harvard University during the years 1907, 1908, and 1910 edited by Professor Sargent and published in 1913. That same year he was awarded an honorary Master of Arts degree from Harvard University for his work on the Bradley Bibliography, and in 1918 he became the Curator of the Herbarium at the Arnold Arboretum, a position he held until his retirement. During Rehder’s 22-year supervision the herbarium grew by 300,000 specimens.

In 1902, Rehder returned to Germany to complete his “Synopsis of the Genus Lonicera,” In 1904, he and Arboretum colleague John George Jack (1861-1949) travelled together in the western United States and in Canada taking photographs and collecting plant specimens. Between 1904 and 1906 Rehder spent time in Europe and in Russia obtaining bibliographic data for the Bradley Bibliography from botanical libraries, herbaria, and museums. He attended the International Botanical Congress of 1905 in Vienna on behalf of Harvard University, and in Dresden in 1906 he married Anneliese Hedwig Schrefeld (1875-1967). The Rehders had three children; Harald Alfred (1907-1996), Gerhard Oskar (1908-1996), and Sylvia Sophie (1912-1996).

The first volume of the Journal of the Arnold Arboretum was issued in 1919, and although Rehder’s name is not listed as an editor until 1926, he had urged its creation and contributed a substantial number of articles. It was not until Sargent’s death in 1927 that Rehder became senior editor, a position he held for the next thirteen years. Also in 1927, the first edition of Rehder’s Manual of Cultivated Trees and Shrubs Hardy in North America was published. Based to a great extent on the taxonomic aspects of woody north-temperate plants in the Arboretum’s living collections, it proved to be such a valuable identification manual for botanists and horticulturalists alike that a second printing was quickly required. A revised second edition was published in 1940, and a reprint of the second edition was published in 1986. In 1997, Rehder’s Manual was chosen as one of “75 Great American Garden Books" by the American Horticultural Society. In his paper “The End of a Generation of Harvard Botanists,” Reed C. Rollins (1911-1998) wrote of Rehder that “In spite of his preoccupation with the technical aspects of taxonomy, he was much interested in the problems of the horticulturist. He provided many horticulturists with individual attention, in addition to the professional guidance they obtained from his published works” ( Taxon 1 (1) 1951). Originally considered by American editors as too botanical for horticultural publications and too horticultural for botanical ones, Rehder’s “Zur Geschichte der Geholzeinfuhrungen nach Nordamerika,” was first published in Mitteilungen der Deutschen dendrologischen Gesellschaft in 1932. In 1946, after being translated back into English by the Arboretum’s librarian, Ethelyn M. Tucker “On the History of the Introduction of Woody Plants into North America” was published Arnoldia.

Rehder made a series of trips to Europe during 1909, 1911, and 1928 and again represented Harvard University and was an active member of the Nomenclature Committee at the International Botanical Congress which was held in 1930 in Cambridge, England. In 1934, Harvard appointed him Associate Professor of Dendrology and the following Rehder travelled to Europe for the last time to attend the International Botanical Congress held in Amsterdam Both he, and the Arboretum’s Director, Elmer Drew Merrill (1876-1956), served International Committee on Nomenclature Vascular Plants.

Being actively involved in professional societies and organizations on both continents Alfred Rehder served as an important connection between colleagues in Europe and the United States, often passing information or requests across the Atlantic Ocean. His correspondence dates from the late 1890s until 1949, nine years after his official retirement, and reflects Rehder’s far ranging interests and connections within the botanical and horticultural world. The collection includes letters to and from colleagues such as Liberty H. Bailey (1858-1954), founder of the the Liberty Hyde Bailey Hortorium at Cornell University in 1935; Heinrich Handel-Mazzetti (1882-1940), an Austrian botanist and early plant explorer in South West China; and Alice Eastwood (1859-1953), Head of the Department of Botany at the California Academy of Sciences about taxonomic and nomenclatural issues. He offered instruction and encouragement to many plant collectors such as Max J. Dinklage (1864-1935), a plant collector in West Africa who was responsible for the earliest major collections from Liberia; Henri Humbert (1887-1967), French Professor at the University of Algiers and botanist and plant collector in Madagascar; Cornelius H. Muller (1909-1997) (also Mueller), internationally recognized authority on Quercus for whom the C.H. Muller Library at the University of California, Santa Barbara is named; and L.J. Brass (1900-1971) who served as botanist on the various Archbold Expeditions for the American Museum of Natural History. Their adventurous letters often describe the exotic places they traveled and the difficulties they encountered obtaining plant specimens. He fielded inquiries from horticulturalists, nurserymen, and plant breeders like J. Horace McFarland (1859-1948) and Niels Ebbesen Hansen (1866-1950). Rehder also answered plant identification requests or provided help with nomenclatural queries from amateur botanists such as Frederick Gillan Floyd (1869-1941) and responded to the many questions posed by a legion of enthusiastic, although often perplexed, gardeners. Rehder took all inquiries seriously, responding promptly to everyone who wrote him.

Beginning in 1915 Rehder maintained a card file of literature references for woody north-temperate plants. In this index, which was referred to by Arboretum staff as the "Rehder Cards," contained all the available references found in in the periodic literature. Rehder noted the botanical names, and their synonyms, of all the plants that had appeared in his Manual. Also recorded were new cultivated woody plants along with new varieties and forms. The index also documented changes in taxonomic interpretation and nomenclature which enabled staff to make any necessary corrections to the living collection’s records and to the plant labels on the specimens growing on the grounds. Until 1998 and the advent of the living collections database, BG-BASE, Arboretum taxonomists continued to add new cards and make annotations to preexisting ones through reviews of current literature and when revisionary, monographic, and floristic studies were undertaken.

Alfred Rehder officially retired in 1940 at age 77, but continued to work at his desk every morning on a comprehensive bibliography of cultivated woody plants based on his index which at that time held close to 150,000 cards. He completed the manuscript for the Bibliography of Cultivated Trees and Shrubs Hardy in the Cooler Temperate Regions of the Northern Hemisphere in 1946, saw this major work through the press, and celebrated its publication with his Arboretum colleagues in June, 1949. He continued on with his regular Arboretum schedule until early July: Alfred Rehder, Associate Professor of Dendrology, Emeritus, died on July 21, 1949.

Over his lifetime Rehder was the author at least 1400 names (>800 species name + >600 varietal or subspecific names) and authored, in both German and English, more than 1,000 scientific articles in botanical and horticultural publications; a complete bibliography was compiled by his granddaughter Anneliese Rehder and was published following Kobuski’s biography of Rehder in the Journal of the Arnold Arboretum. Over 60 genera and species are named in Rehder’s honor. Not as well-known as his research and writing is the fact that Rehder took some of earliest images of the Arboretum most of which are filed by genus in species in the Arboretum’s historic photograph collection; at the end of the finding aid scanned pages from the Arboretum’s accession records of photographs lists the images taken by Rehder.

At the time of his death Rehder was a member of the following Botanical and Horticultural Societies:

Honorary Fellow of the Botanical Society of Edinburgh Honorary Fellow of the Royal Horticultural Society of London Fellow of the American Academy of Arts and Sciences Fellow of the American Association for the Advancement of Science Honorary Membership in Deutsche Dendrologische Gesellschaft Honorary Membership in Ceskoslovenske Dendrolijike Spolecnost Honorary Membership in Rhododendron Society Honorary Membership in Pennsylvania Horticultural Society Corresponding Member of the Peking Society of Natural History Corresponding Member of the Botanical Society of Japan Foreign Member of the Linnean Society of London Member of the Society for Horticultural Science Member of the Deutsche Botanische Gesellschaft Member of the Boston Natural History Society Member of the New England Botanical Club Member of the Society of Plant Taxonomists Member of the Botanical Society of America

Arrangement note

This collection contains six series:
Missing Title
  1. Biographical Material
  2. Photographs of Alfred Rehder
  3. Papers on Nomenclature
  4. Publications
  5. Rehder Card Index
  6. Photographs by Alfred Rehder


This collection was transferred from the Arnold Arboretum’s departmental holdings to the Arboretum’s Archives in 1984.

Related Archival Materials note

The majority of Alfred Rehder correspondence can be found in the Arnold Arboretum Correspondence Database.

See also X A-4 Accession Lists – Historic Photographs, Box Inventory, Folder 4 - Photographs taken in the Arnold Arboretum, A-937 to 1300 by A. Rehder. 1898-1928 and Folder 19 – M1-M1315. Photos by E. H. Wilson and A. Rehder. (and others)

Processing Information note

June 2011, Liz Francis. Historical Note by Sheila Connor, 2012
Alfred Rehder (1863-1949) papers, 1898-1949.
Finding aid prepared by Larissa Glasser

Repository Details

Part of the Arnold Arboretum Archives Repository

The Arnold Arboretum Horticultural Library is a specialized collection devoted to the study of temperate woody plants. We collect works on botany, horticulture, floras, urban forestry and taxonomy. The library contains more than 25,000 volumes and 40,000 photographs, and includes an archive that both documents the Arboretum's history and is a repository for 19th, 20th, and 21st century horticultural and botanical collections.

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