Of, pertaining to, or resembling a grass(adjective)
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Use "graminaceous" in a sentence
"But the graminaceous plants do not usually have bacteria associated with their roots to fix nitrogen from the air."
""Commonness will prevail," as De Candolle said in speaking of the graminaceous plants."
"Silica, indeed, if at all capable of producing a beneficial effect, ought to be useful to these crops, either by strengthening the straw, or stems of graminaceous plants, or otherwise benefiting them; but, after deducting the amount of silica from the total amount of mineral matters in the wheat produced from one acre, only a trifling quantity of other and more valuable fertilizing ash constituents of plants will be left."