Collins, Holden & Setchell, Phycoth. Bor.-Amer.
Collins, F.S.; Holden, I.; Setchell, W.A. [1-2300]

Brown University - Algae
Catalog #: ABRU00005091
N. L. Gardner s.n.
Staurastrum protractum L.N.Johnson
United States, California, Botanical Laboratory, University of California, Berkeley, CA

University Herbarium, University of California, Berkeley
Catalog #: UC1828025
N. L. Gardner #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Cultivated in the Botanical Laboratory of the University of California.

University Herbarium, University of California, Berkeley
Catalog #: UC1828026
N. L. Gardner #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Cultivated in the Botanical Laboratory of the University of California.

University of Michigan
Catalog #: 736528
N.B. Reynolds #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Botanical Laboratory, University of California, Berkeley

University of Michigan
Catalog #: 736529
N.B. Reynolds #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Botanical Laboratory, University of California, Berkeley

Michigan State University Algae
Catalog #: MSC0184879
N.L. Gardner #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Botanical Laboratory, University of California, Berkeley

Miami University - Algae
Catalog #: 000210310
N.L. Gardner #s.n. 00 April 1917
Staurastrum protractum L.N.Johnson
United States, California, Alameda, Botanical Laboratory, University of California, Berkeley