Which is a genus of tree, Gymnocladus or Nautilocalyx?
Gymnocladus: Gymnocladus (Neo-Latin, from Greek γυμνὀς, "gymnos", naked + κλάδος, "klados", branch) is a small genus of leguminous trees. Nautilocalyx: Nautilocalyx is a genus of plant in family Gesneriaceae.
Gymnocladus