X. humbertii Cavaco 1950 is a small tree 6-8 m tall known from only a single collection made in transitional vegetation between sclerophyllous forest and dry bush (800-900 m elevation). It was collected from the locality where now Andohalela National Park exists (Toliara province).
X. perrieri F. Gérard 1919 is a tree c. 4-10 m tall that has been recorded at scattered localities from near Morondava, Ankarafantsika National Park and the Lokia river basin east of Ambilobe within Madagascar’s dry bioclimatic region (Antsiranana, Mahajanga and Toliara provinces). Vernacular name – Zahana.
X. richardii (Baillon) Baillon (1872) 1884 is a tree c. 4-20 m tall, ranging from sea level to over 1,500 m elevation in areas with a humid bioclimate in northeastern Madagascar, with one population recorded in the far southeast (Antsiranana, Toamasina and Toliara provinces). Vernacular names – Fakody, Fombaotoafo, Pesoala, Takodibe, Tamboro, Tsikody zahana, Vahitoambody, Voakoropetaka, Voantiambody, Voantsatroka.
X. sambiranensis Lowry, G.E. Schatz 2002 is a shrub to tree 3-12 m tall distributed in the Sambirano region (subhumid bioclimate) from south of Maromandia north to the Ambanja area (Antsiranana and Mahajanga provinces). Vernacular names – Sofiakomba, Sofiankomba, Sofikomba, Sofinakomba, Sofinkomba.
X. speciosa Lowry, G.E. Schatz 2002 is a large shrub or tree to 20 m tall. It is narrowly distributed in an area with a dry to subhumid bioclimate extending from the Ambato Peninsula and the lower Ifasy river valley north to near Ambilobe (Antsiranana province). Vernacular name – Marabanty.