Kainulainen, K. (2021). A taxonomic revision of Melanoxerus (Rubiaceae), with descriptions of three new species of trees from Madagascar. Candollea 76: 105–116. In English, English and French abstracts.
This paper provides a taxonomic revision of Melanoxerus Kainul. & Bremer (Rubiaceae) – a genus of deciduous trees with eye-catching flowers and fruits that is endemic to Madagascar. Descriptions of three new species, Melanoxerus antsirananensis Kainul., Melanoxerus atropurpureus Kainul., and Melanoxerus maritimus Kainul. are presented along with distribution maps and a species identification key. The species distributions generally reflect the ecoregions of Madagascar, with Melanoxerus antsirananensis being found in the dry deciduous forests of the north; Melanoxerus atropurpureus in the inland dry deciduous forests of the west; Melanoxerus maritimus in dry deciduous forest on coastal sands; and Melanoxerus suavissimus (Homolle ex Cavaco) Kainul. & B. Bremer in the dry spiny thicket and succulent woodlands of the southwest.