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

Brown University - Algae
Catalog #: ABRU00003480
N. L. Gardner s.n. 14 April 1901
Zygnema chalybeospermum Hansgirg
United States, California, Boswell, near Berkeley, CA

Yale University Herbarium
Catalog #: YU.106566
Nathaniel Lyon Gardner s.n. 14 April 1901
Zygnema chalybeospermum Hansgirg
United States, California, Boswell, near Berkeley, CA