Japanese honeysuckle (Lonicera japonica), multiflora rose (Rosa multiflora), purple loosestrife (Lythrum salicaria), common buckthorn (Rhamnus cathartica), glossy buckthorn (Rhamnus frangula), saw-toothed buckthorn (Rhamnus arguta), dahurian buckthorn (Rhamnus davurica), Japanese buckthorn (Rhamnus japonica), Chinese buckthorn (Rhamnus utilis), kudzu (Pueraria lobata), exotic bush honeysuckles (Lonicera maackii, Lonicera tatarica, Lonicera morrowii, and Lonicera fragrantissima), exotic olives (Elaeagnus umbellata, Elaeagnus pungens, Elaeagnus angustifolia), salt cedar (all members of the Tamarix genus), poison hemlock (Conium maculatum), giant hogweed (Heracleum mantegazzianum), Oriental bittersweet (Celastrus orbiculatus), and lesser celandine (Ficaria verna), teasel (all members of the Dipsacus genus), and Japanese, giant, and Bohemian knotweed (Fallopia japonica, syn. Polygonum cuspidatum; Fallopia sachalinensis; and Fallopia x bohemica, resp.) are hereby designated exotic weeds. Upon petition the Director of Natural Resources, by rule, shall exempt varieties of any species listed in this Act that can be demonstrated by published or current research not to be an exotic weed as defined in Section 2.