ague weed(n = noun.plant) agueweed, five-flowered gentian, gentiana quinquefolia, gentianella quinquefolia, stiff gentian - gentian of eastern North America having clusters of bristly blue flowers;
is a kind of gentian
is a member of gentianella, genus gentianella

ague, ague grass, ague root, alligator weed, butterfly weed, cancer weed, consumption weed, crazy weed, devil's weed, dill weed, dyer's weed, french weed, ghost weed, horsefly weed, jamestown weed, jimson weed, joe-pye weed, klammath weed, mad-dog weed, orchilla weed, pickerel weed, pineapple weed, polecat weed, rattle weed, rattlesnake weed, rheumatism weed, scorpion weed, spotted joe-pye weed, stemless golden weed, stinking weed, styptic weed, trumpet weed, turpentine camphor weed, turpentine weed, weed, weed killer, weed out