This collection contains one folder of letters to Abrams from Willis Linn Jepson (1867–1946), professor of botany at University of California at Berkeley, and copies of Abrams’ letters (1920–1943) to Jepson. The correspondence relates mainly to Jepson’s work on Erigoneae, intended for the second volume of Abrams’ Illustrated Flora of the Pacific States, and Jepson’s eventual inability to finish it in time for the volume’s publication in 1937. There is also a statement (1939, 3 typescript pages) to Abrams signed by Jepson regarding the publication dates of Jepson’s A Manual of the Flowering Plants of California (Berkeley, University of California, 1925), in which he also refers to the publication policies of Edward L. Greene (1843–1915), whom he had years earlier served as an assistant. There is also a letter (1948) from Ray L. Wilbur, chancellor of Stanford University, regarding Abrams’ election to honorary membership in the California Academy of Sciences.

In addition, there are two volumes containing letters to Abrams from friends, former students and colleagues. One volume was compiled upon his retirement from teaching in 1940, the other on his eightieth birthday (1 October 1954).