plant genus - a genus of plants

family Graminaceae, family Gramineae, family Poaceae, Graminaceae, Gramineae, grass family, Poaceae - the grasses: chiefly herbaceous but some woody plants including cereals; bamboo; reeds; sugar cane

oat - annual grass of Europe and North Africa; grains used as food and fodder (referred to primarily in the plural: `oats')