J. F.  Macbride, ?Further notes on the Boraginaceae?, Contributions from the Gray Herbarium of Harvard University, vol. 49, pp. 16?22, 1917.

J. F.  Macbride, ?Certain Boraginaceae, new or transferred?, Proceedings of the American Academy of Arts and Sciences, vol. 51, pp. 541 - 548, 1916.

J. F.  Macbride, ?Flora of Peru: Boraginaceae?, Field Museum of Natural History, Botanical Series, vol. 13, no. 5, 2, pp. 539 - 609, 1960.