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 macrantha Poa macrantha is a species of grass known by the common names seashore bluegrass and large-flowered sand dune bluegrass. It is native to the west coast of North America from Alaska to northern California, where it grows in sand dunes and other beach habitat.