Literature

• Mori, S.A., Gracie, C.A. 2007. Flowering Plants. Plants and Lichens of Saba Virtual Herbarium of The New York Botanical Garden. [link]
• The Plant List 2013. The Plant List version 1.1. [link]
• WCSP 2017. World Checklist of Selected Plant Families. Facilitated by the Royal Botanic Gardens, Kew. [link]

Literature references linked to higher taxa

• Encyclopedia of Life. [link] (Rubiaceae)