De Block, P., F. Rakotonasolo, A. Vrijdaghs, and S. Dessein. “Two New Species of Phialiphora (Spermacoceae, Rubiaceae) Exemplify Drought Adaptations in Western Madagascar”. Plant Ecology and Evolution, Vol. 153, no. 2, July 2020, pp. 267-82, doi:10.5091/plecevo.2020.1675.