This collection includes the correspondence (four letters, 1946) of Esau and Gilbert M. Smith (1885–1959) of Stanford University, concerning a possible arrangement between them for a book on the morphology of angiosperms, based on Esau's revisions of Smith's notes. The book that did result was Esau's Plant Anatomy (New York, Wiley, 1953; HI call no. DK E74P 965). The collection also contains undated notes (6 typescript pages) on morphology.