Contribution from the University of Michigan Herbarium - University of Michigan Herbarium - Ann Arbor, Michigan (Michigan University of Michigan Herbarium - Ann Arbor, Michigan, 1939)
-Existencias: 1939-1940 v.1-4 ; 1941-1942 v. 6-8; 1969-1972 v.9, no. 2-8; 1973 v. 10; 1973 v. 11, no. 1-5; 1974 v.12, no.3; 1978-2007 v. 13-25