Allenanthus
Allenanthus was a genus of flowering plants in the family Rubiaceae but is no longer recognized. It has been sunk into synonymy with Machaonia.
Taxonomy
Allenanthus was named by Paul Standley in 1940 in Annals of the Missouri Botanical Garden. It was named in honor of Paul Hamilton Allen.Until 2004, two species had been recognized, but fieldwork has shown that there is a continuum of variation between them.
Comparisons of morphological characters and DNA sequences have shown that Allenanthus is embedded in Machaonia. This was confirmed by a molecular phylogenetic study of the subfamily Cinchonoideae in 2010. Because of these results, Allenanthus is no longer maintained as a separate genus.