sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne's Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. ABSTRACT. The circumscription of the Fabroniaceae is revisited based on phylogenetic inferences from published rps4 (cpDNA) and nad5 (mtDNA) sequences. Only Ischyrodon forms a clade with Fabronia, a relationship defined by the wavy-walled exothecial cells as a possible synapomorphy. The genus Levierella is nested within the Entodontaceae, Dimerodontium among taxa traditionally associated with Leskeaceae and the position of Rhizofabronia is uncertain.