gamagrass
/ˈɡaməˌɡrɑːs/ /ˈɡaməˌɡras/(also gammagrass)
noun
Any of several tall, clump-forming prairie grasses of the genus Tripsacum native chiefly to Central and North America; especially (more fully eastern gamagrass) Tripsacum dactyloides, cultivated in the southern United States and elsewhere as a forage grass.
Origin
Mid 19th century. Probably from a variant or alteration of Spanish grama or its etymon grama + grass, although grama normally denotes a different type of grass.