Nerium oleander, commonly known as oleander or rosebay, is a shrub or small tree cultivated worldwide in temperate and subtropical areas as an ornamental and landscaping plant. It is the only species currently classified in the genus Nerium, belonging to subfamily Apocynoideae of the dogbane family Apocynaceae. It is so widely cultivated that no precise region of origin has been identified, though it is usually associated with the Mediterranean Basin.
Nerium
A wadi in Libya
Infected with X. fastidiosa in Phoenix
An Oleander, an 1882 painting by Lawrence Alma-Tadema.
Apocynaceae is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison. Members of the family are native to the European, Asian, African, Australian, and American tropics or subtropics, with some temperate members. The former family Asclepiadaceae is considered a subfamily of Apocynaceae and contains 348 genera. A list of Apocynaceae genera may be found here.
Apocynaceae
Alstonia scholaris, arrangement of leaves
Rhigospira quadrangularis, portion of a plant. 1) the inflorescence and 2) a flower, to scale; 3) corolla in bud, showing the pyramidal form of the erect segments in aestivation and 4) the same cut open when expanded, showing their simple sinistrorse convolution and the nearly basal position of the stamens, both magnified; 5) the calyx, disk, very short style, clavuncle, and stigmata, to scale; 6) the same, magnified; 7) a stamen, much magnified.
Acokanthera oblongifolia