A monograph of the Hauyeae and Gongylocarpeae, tribes of the Onagraceaev. 16No. 12287–298
Smith, John Donnell and Rose, J. N. 1913. "A monograph of the Hauyeae and Gongylocarpeae, tribes of the Onagraceae." Contributions from the United States National Herbarium, 16, (12) 287–298.