problematic, bothersome, troubling, vexing, nettlesome, worrisome, problematical, aggravating, tricky, dicey, dangerous, irritating, irksome, perplexing, unsettling, undesirable, difficult, costly, frustrating, painful, recalcitrant, touchy, puzzling, annoying, inconvenient, unpleasant, disconcerting, nagging, unsavory, contentious, nasty, prickly, thorny, distressing, complicated, daunting, perilous, wayward, baffling, balky, intractable, unstable, risky, unpalatable, unwelcome, damaging, questionable, unappealing, unnerving, controversial, disruptive, bad, embarrassing, useful, infuriating, disturbing, onerous, disastrous, messy, doubtful, niggling, exasperating, sticky, pesky, frightening, unfriendly, iffy, sore, tempting, distracting, unsightly, persistent, inopportune, uncomfortable, erratic, beneficial, discomforting, awkward, strained, wonky, helpful, confusing, unattractive, galling, ineffective, disquieting, important, dodgy, debilitating, crucial, odious, unappetizing, inflamed, benign, challenging, unpopular, inconsistent, maddening, pesty, alarming, unadvisable, peculiar, apaches, austrian, blackfeet, british, canaanite, corns, dependant, encumbrance, febrile, foaming, franks, germans, guests, interlopers, intruders, magyars, moslem, muscovite, northerners, disagreeable, ticklish, unimportant

artemisia filifolia, berteroa incana, bottle-grass, bottle grass, brat, broad-leaved plantain, cart-track plant, common plantain, eichhornia crassipes, eichhornia spesiosa, eradicator, erysimum cheiranthoides, euphorbia esula, exterminator, family plantaginaceae, fractious, green bristlegrass, green foxtail, hieracium aurantiacum, hieracium praealtum, hoary alison, hoary alyssum, holy terror, horse thistle, king devil, lactuca scariola, lactuca serriola, leafy spurge, little terror, marsh cress, orange hawkweed, pilosella aurantiaca, plantaginaceae, plantago major, plantain family, prickly lettuce, rorippa islandica, rough bristlegrass, russian cactus, russian thistle, russian tumbleweed, salsola kali tenuifolia, sand sage, setaria viridis, silvery wormwood, terminator, terror, tumbleweed, water hyacinth, water orchid, white-man's foot, whiteman's foot, wolf's milk, wormseed mustard, yellow hawkweed, yellow watercress

difficult, hard