Ellis, N. Amer. Fungi
J.B. Ellis [1 - 1500, plus extras]

USDA United States National Fungus Collections
Catalog #: BPI 605089
s.n.
Sphaerotheca humuli (DC.) Burrill
United States, Pennsylvania, Philadelphia

Michigan State University Herbarium non-lichenized fungi
Catalog #: MSC0253778
J. W. Eckfeldt s.n.
Spaherotheca castagnei
United States, Pennsylvania, Philadelphia;

Miami University, Willard Sherman Turrell Herbarium
Catalog #: 000247552
J. W. Eckfeldt #557c
Sphaerotheca humuli var. fuliginea (Schltdl.) E.S. Salmon
United States, Pennsylvania, Philadelphia

University of Wisconsin-Madison Herbarium
Catalog #: WIS-F-0087387
J. W. Eckfeldt #557c
Sphaerotheca humuli var. fuliginea (Schltdl.) E.S. Salmon
United States, Pennsylvania, Philadelphia

Purdue University, Kriebel Herbarium
Catalog #: PUL00032611
JW Eckfeldt s.n.
Sphaerotheca castagnei Lév.
United States, Pennsylvania, Phiadelphia, Phiadelphia;