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

Brown University - Algae
Catalog #: ABRU00004170
C. G. Pringle s.n. 12 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, Tlalpam, Valley of Mexico, Mexico

University of Michigan
Catalog #: 677650
C.G. Pringle #s.n. 21 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, México, Tlalpam, Valley of Mexico

Michigan State University Algae
Catalog #: MSC0183647
C.G. Pringle #s.n. 21 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, México, Tlalpam, Valley of Mexico

Miami University - Algae
Catalog #: 000188507
C.G. Pringle #s.n. 21 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, México, Tlalpam, Valley of Mexico

Drexel University, Academy of Natural Sciences - Algae
Catalog #: PH00142163
dbbe2063-f3fa-4f94-a2ee-9e6e7810153c
Cyrus G. Pringle #s.n. 12 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, Tlalpam, Valley of Mexico, Mexico

Yale University Herbarium
Catalog #: YU.094477
Cyrus Guernsey Pringle s.n. 12 August 1896
Nitella opaca (C.Agardh ex Bruzelius) C.Agardh
Mexico, Tlalpam, Valley of Mexico, Mexico