Callmander, M. W., E. A. Tripp & P. B. Phillipson (2014). A new name in Ruellia L. (Acanthaceae) for Madagascar. Candollea 69: 81–83. In English, English and French abstracts.

Recent molecular phylogenetic studies showed that the endemic Malagasy Eusiphon Benoist is nested within Ruellia L. (Acanthaceae). The authors here propose a new name to replace an illegitimate later homonym for Eusiphon longissimum Benoist: Ruellia quartziticola Callm., E. Tripp & Phillipson. This striking species is rare in the wild and endemic to the quartzite veins of the Highlands of Madagascar. Following IUCN Red List Categories and Criteria, Ruellia quartziticola is considered to be “ Critically Endangered”.