Source : Webster's Revised Unabridged Dictionary (1913)

Bunch grass \Bunch" grass`\ (Bot.)
   A grass growing in bunches and affording pasture. In
   California, {Atropis tenuifolia}, {Festuca scabrella}, and
   several kinds of {Stipa} are favorite bunch grasses. In Utah,
   {Eriocoma cuspidata} is a good bunch grass.

Source : WordNet®

bunch grass
     n : any of various grasses of many genera that grow in tufts or
         clumps rather than forming a sod or mat; chiefly of
         western United States [syn: {bunchgrass}]