Manothrix is a genus of plants in the family Apocynaceae, first described as a genus in 1878. The entire genus is endemic to Brazil.
In 1993, Cecilia Carmen Xifreda published an analysis of the two species of the genus and concluded that Manothrix nodosa = Mesechites trifidus (Apocynaceae) and Manothrix valida = Hillia parasitica (Rubiaceae). Mesechites trifidus and Hillia parasitica were both described before Manothrix, so have priority as names.