are Cladanthus and Oxydendrum both plant genus ?
Cladanthus Cladanthus is a genus of plants in the family sunflower family, native to the Mediterranean region.
Catharanthus Catharanthus is a genus of flowering plants in the dogbane family, Apocynaceae. Like genus "Vinca", they are known commonly as periwinkles. There are eight known species. Seven are endemic to Madagascar, though one, "C. roseus", is widely naturalized around the world. The eighth species, "C. pusillus", is native to India and Sri Lanka. The name "Catharanthus" comes from the Greek for "pure flower".