The LuEsther T. Mertz Library at the New York Botanical Garden is one of many partners on the Biodiversity Heritage Library Field Notes Project which was generously funded by the Council of Library and Information Resources (CLIR). As its contribution to the project, NYBG selected 91 field notebooks for digitization. Nine different collectors are represented in the selected volumes. The bulk of the selected volumes — a total of 61 — document the botanical collecting of Dr. Arthur Cronquist (1919-1992), a pre-eminent twentieth-century American botanist who spent most of his career at NYBG. The Cronquist field notes date from 1941 to 1990 and while most document work done in the continental United States, other countries are also represented including the former Soviet Union, a region of great interest to Cronquist.
Dr. Arthur Cronquist
|Arthur Cronquist in his office at NYBG, 1980s.|
Cronquist’s professional accomplishments were numerous and varied. He was recognized internationally as an expert in the Asteraceae (also known as Compositae), the largest plant family in terms of number of described species. His other professional achievements include floristic studies, development of a taxonomic classification system and authorship of several widely used botany textbooks. Floristics refers to study of the types, numbers, distributions and relationships of plant species within a given, delimited area. Theodore Barkley wrote about Cronquist:
“Over the years, he was variously connected to nearly every major floristic project in temperate North America (and even one in the Galapagos), whether as author, coauthor, contributor, or consultant.” 
The list of projects worked on by Cronquist includes Compositae in The New Britton & Brown Illustrated Flora (Gleason, 1952); Compositae in Flora of Idaho (Davis, 1952), Vascular Plants of the Pacific Northwest (Hitchcock et al., 1955-1969), Manual of the Vascular Plants of the Northeastern United States and Adjacent Canada (Gleason & Cronquist, 1963 [ed. 2, 1991]) and the fifth volume of the multi-volume Intermountain Flora (1994) to name just a few.
|Erigeron maguirei, named by Cronquist in honor of Dr. Bassett Maguire, an early mentor. Endemic to Utah, Maguire’s Fleabane is a species of conservation concern and is a member of the Asteraceae, one of Cronquist’s major research foci.|
While eulogizing Cronquist at a memorial service held at NYBG in 1992, Dr. Peter Raven compared the botanical achievements of Cronquist to those of Linnæus.  Other scientists have called him the twentieth-century Asa Gray, considered by many to be the most important American botanist of the nineteenth century. Arthur Cronquist died on March 22, 1992, while studying specimens in the herbarium of Brigham Young University in Provo, Utah.
The Field Notes
|Penstemon subulatus Jones, Cronquist 10561,
from Nevada, Arizona, California, 1966, [numbers 10554-10649]. http://s.si.edu/2nQpjqo.
Cronquist’s botanical field notebooks are typical of other botanical field notebooks and show how botanists document their field work and collect specimens. The image above shows one page in a field notebook created by Cronquist in 1966. At the top of the page, the number “10561” is visible. Botanists assign sequential numbers to the specimens that they collect throughout their careers. This number, when appended to the collector’s name, e.g. Cronquist 10561, forms an identifier that is retained when the specimen is subsequently deposited in a herbarium. The descriptive information recorded in the field notebook, e.g. the date, location and elevation, is copied from the field notes to a specimen label. The dried, pressed specimen and the specimen label are then mounted on a large sheet of paper. The image below shows a herbarium sheet for the specimen described on this page in Cronquist’s field notes and comes from the William and Lynda Steere Herbarium at New York Botanical Garden.
|Penstemon subulatus Jones, Herbarium Specimen|
 Barkley, Theodore M. (1996). On the Contribution of Arthur Cronquist to Botanical Science at The New York Botanical Garden. Brittonia, 48(3), 372-375. Retrieved from http://www.jstor.org/stable/2807800
 Lamont, Eric E. (1994). Arthur Cronquist (1919-1992). Bulletin of the Torrey Botanical Club, 58, 126-129. Retrieved from https://www.biodiversitylibrary.org/part/254875
University of Florida Herbarium. Preparation of Plant Specimens for Deposit as Herbarium Vouchers. Retrieved from https://www.floridamuseum.ufl.edu/herbarium/voucher.htm
The BHL Field Notes Project is funded by the Council on Library and Information Resources (CLIR).