Lopes da Cunha Neto, Israel, Veronica Angyalossy, and Norman A. Douglas. “What Are the "sticky rings" On Stems of Anulocaulis and Related Taxa (Nyctaginaceae) from Arid Regions?”. Journal of the Botanical Research Institute of Texas 13, no. 2 (October 31, 2019): 477-485. Accessed December 5, 2021. https://journals.brit.org/jbrit/article/view/803.