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COLLECTION Identifier: gra00078

Asa Gray correspondence files of the Gray Herbarium

Scope and Contents

This collection, approximately 1820-1904, includes the personal correspondence of Asa Gray and Sereno Watson, official correspondence of other Herbarium staff, and a small amount of correspondence of noted botanists who were not affiliated with Harvard.

Gray correspondence contains letters from several of the most distinguished European and American scientists of the 19th century, including George Bentham, Charles Darwin, Joseph Henry, Joseph Dalton Hooker, William Jackson Hooker, and John Torrey. Letters include important biographical information and also document the early history of botany in the United States. The Darwin correspondence contains a letter to Gray establishing Darwin's precedence in developing a theory of natural selection.

Selected letters of Asa Gray were published in: Gray, Jane Loring, ed. Letters of Asa Gray (1893).


  • 1820-1931
  • Majority of material found in 1820-1904


Conditions Governing Access

The collection is available by appointment for research. Researchers must register and provide one form of valid photo identification. Please contact for additional information.


12 linear feet (1 file cabinet labeled H1, 3 flat oversize boxes)

Historical note

The Gray Herbarium originated with the gift of Asa Gray's herbarium and library to Harvard in 1864. Early curators and directors were Sereno Watson (1874-1892); Benjamin Lincoln Robinson (1892-1935); and Merritt Lyndon Fernald (1935-1947).
Biographical note Often called the “Father of American Botany,” Asa Gray was instrumental in establishing systematic botany as a field of study at Harvard University and, to some extent, in the United States. His relationships with European and North American botanists and collectors enabled him to serve as a central clearing house for the identification of plants from newly explored areas of North America. He also served as a link between American and European botanical sciences. Gray regularly reviewed new European scientific works and was an early proponent of Charles Darwin's theory of natural selection.

Asa Gray was born in Sauquoit, New York, on November 18, 1810, to Roxana Howard Gray and Moses Wiley Gray. He attended grammar school in Clinton and continued his education at Fairfield Academy, enrolling in Fairfield’s College of Physicians and Surgeons in 1829. Gray’s interest in botany developed during this time and he began corresponding with botanists Lewis Caleb Beck and John Torrey.

Gray completed his M.D. in 1831 and accepted a teaching position at a boys’ school in Utica, New York. For the next few years he divided his time between teaching, collecting, and working as Torrey’s assistant. His first publications appeared in the winter of 1834-1835. In 1836 he became curator at the New York Lyceum of Natural History. He also began work on a North American flora with Torrey. The first volume of “Flora of North America”was published in two parts in 1838.

Gray was appointed botanist of the United States Exploring Expedition under Charles Wilkes in 1836 but withdrew after the expedition was delayed. In 1838 he accepted an appointment as Professor of Botany at the University of Michigan on condition that he first be allowed a year of study in Europe. He departed in November 1838 and spent the next 12 months visiting herbaria and meeting prominent botanists in Great Britain, France, Germany, Switzerland, Italy, and Austria. Complications at Michigan prevented Gray from starting the professorship there. Instead he returned to New York to work on the second volume of “Flora.”

In 1842 he moved to Cambridge, Massachusetts, to accept the newly endowed Fisher Professorship at Harvard. He remained in that position for the rest of his life. In addition to teaching Gray assumed responsibility for the Harvard Botanical Garden and built a herbarium and library. He was a prolific correspondent and writer. His 1848 “Manual of the Botany of the Northern United States” became the standard field manual for botanists in the Northeast and his textbooks were used in classes across the U.S.

In 1848 Gray married Jane Lathrop Loring. She assisted him in his work and accompanied him on trips to Europe, the Allegheny Mountains, and to the American West.

Gray died in Cambridge on January 30, 1888.
Biographical note Sources

Deane W. 1888. Asa Gray. Bull. Torrey Bot. Club. 15(3):59-72.

Farlow WG. 1895. Memoir of Asa Gray. 1810-1888. Biogr. Mem. Natl. Acad. Sci. U.S.A. 3:161-175.

Gray A. 1894. Autobiography. In: Gray JL. Letters of Asa Gray. Boston (MA): Houghton, Mifflin and Company.


Arranged alphabetically by correspondent.

Some files related to the United States Exploring Expedition are filed first under the expedition name and then alphabetically by correspondent.


There is no official documentation on the provenance of this collection. It is likely that the Asa Gray correspondence files were left at the Gray Herbarium by Asa Gray after his death in 1888 or were presentd as a gift by his wife Jane Gray. The collection also includes letters to Sereno Watson and other members of the Gray Herbarium staff from 1870-1906. Sereno Watson's correspondence is included in this collection because he worked very closely with Asa Gray on Gray Herbarium matters.

Mary Day took charge of a file of historic letters during her tenure as librarian of the Gray Herbarium, 1893-1923. Mary Day and Jane Gray likely curated this collection. It is unknown how later staff or succeeding librarians curated the collection.

Occassionally Asa Gray or Sereno Watson correspondence is found with herbarium specimens. When that occurs the letter is removed from the herbarium and it is transfered to the Archives to incorporate into this collection. A photocopy of the letter remains with the specimen and a photocopy of the herbarium label and barcode accompany the letter.

Correspondence after 1904 that relates to Gray Herbarium business is in the Administrative correspondence of the Gray Herbarium collection.

Resources: Robinson BL. Mary Day. Rhodora. 26:41-47.

Boxed correspondence

  1. Oversize box 1: William Henry Harvey (1826-1869).
  2. Oversize box 2: Joseph Henry (1838-1878); William Starling Sullivant (1840-1857).
  3. Oversize box 3: George Engelmann 1840-1884 (oversize correspondence only); John Torrey (1831-1873).

Existence and Location of Copies

Letters of George Bentham, Charles Darwin, Joseph Dalton Hooker, Joseph Prestele, Charles Wilkins Short, Joachim Steetz, Thomas Minott Peters, and Truman George Yuncker were microfilmed.
Digitization note In 2007-2008, the Harvard Library began the Open Collections project to digitize materials related to scientific expeditions. The Botany Libraries contributed published and unpublished material from the United States Exploring Expedition, 1838-1842. Sixteen files from this collection were part of the project.
These files from the Asa Gray correspondence files of the Gray Herbarium were part of the Open Collections Project:
  1. William Brackenridge letters, 1850-1856
  2. Joseph Pitty Couthouy letters, 1837-1856
  3. James Dwight Dana letters, 1836-1886
  4. Mahlon Dickerson letters, 1836
  5. William Henry Harvey letters, 1826-1869
  6. Joseph Henry letters, 1838-1878
  7. Joseph Dalton Hooker letters, 1844-1872
  8. Edward Palmer letters, 1879-1891
  9. Charles Pickering letters, 1836-1877
  10. William Startling Sullivant letters, 1840-1857
  11. John Torrey letters, 1831-1873
  12. United States Exploring Expedition: Drayton, Joseph, 1850-1856
  13. United States Exploring Expedition: Lewis, George, 1856-1857
  14. United States Exploring Expedition: Pearce, James Alfred, 1850-1852
  15. United States Exploring Expedition: Stuart, Frederick, 1859-1873
  16. United States Exploring Expedition: Wilkes, Charles, 1847-1874
Digitization note In 2014, the Botany Libraries digitized the rest of this collection. Some correspondents have two digital files because some letters were digitized in Open Collections and the rest were digitized in 2014. These correspondents have two digital files: James Dwight Dana; Joseph Dalton Hooker; George Lewis; James Alfred Pearce; John Torrey.

Related Materials

Related collections at the Harvard Botany Libraries:
  1. Administrative correspondence of the Gray Herbarium and Harvard University Herbaria, 1890-1965.
  2. Botany Libraries photograph collection.
  3. Asa Gray papers, 1830-1953.

Variant title

Collection formerly referred to as: Historic letters collection, 1838-1892 and Asa Gray correspondence files, 1820-1904.
Harvard University. Gray Herbarium. Asa Gray correspondence files of the Gray Herbarium, 1820-1931, bulk 1820-1904: A Guide.
Botany Libraries, Gray Herbarium Library, Harvard University.
Description rules
Language of description

Repository Details

Part of the Botany Libraries, Gray Herbarium Library, Harvard University Repository

Harvard University Herbaria
22 Divinity Ave
Cambridge MA 02138 USA
(617) 495-2366