are Cladanthus and Oxydendrum both plant genus ?
Oxydendrum Sourwood or sorrel tree, Oxydendrum arboreum, is the sole species in the genus Oxydendrum, in the family Ericaceae. It is native to eastern North America, from southern Pennsylvania south to northwest Florida and west to southern Illinois; it is most common in the lower chain of the Appalachian Mountains. The tree is frequently seen as a component of oak-heath forests.
Otacanthus Octacanthus is a genus in the Plantaginaceae family consisting of up to 5 species which occur in Brazil. They are usually soft-wooded shrubs or small trees, growing at very sunny spots. The flowers are showy and zygomorphic with big lips (labella).