The Collaborative International Dictionary
Gramineous
Gramineous \Gra*min"e*ous\, a. [L. gramineus, fr. gramen, graminis, grass.] (Bot.) Like, Or pertaining to, grass. See Grass, n., 2.
Douglas Harper's Etymology Dictionary
gramineous
1650s, from Latin gramineus (adj.) "of grass, grassy," from gramen "grass" (see graminivorous).\n
Wiktionary
gramineous
a. Of or pertaining to plants in the grass family (''Gramineae'').