Which of these names is a genus of plant that consists of grass species:  Poa or Gymnocladus?
Gymnocladus Gymnocladus (Neo-Latin, from Greek γυμνὀς, "gymnos", naked + κλάδος, "klados", branch) is a small genus of leguminous trees. The common name coffeetree is used for this genus.
Poa arachnifera Poa arachnifera, the Texas bluegrass, is a species of grass.