Azollophyllum primaevum Azolla primaeva is an extinct species of "water fern" in the family Salviniaceae known from Eocene fossils from the Ypresian stage (56 to 48 million years ago), found in southern British Columbia.

[1] Placement of the species was formally changed with the publication of a paper written by Chester A. Arnold[1] based on new fossil specimens collected near the former mining camp of Ashnola, British Columbia, approximately 8 miles south of Princeton along the Similkimeen River.

The fossils were recovered from strata of the Allenby Formation, at the time considered Oligocene age,[1] but now known to be of the Early Middle Eocene.

[1] Arnold notes that with the placement of A. primaeva into the genus Azolla means that its description in 1890 was actually the earliest species described from the fossil record.

[1] Fossil specimens of Azolla have been recovered from the closely related strata of the Klondike Mountain Formation around Republic, Washington, but have not been described to species.