Weeds and Invasive Plants

U.S. federal noxious weeds Plants included within the Federal Noxious Weed List effective as of December 10, 2010 (Last updated March 21, 2017 for synonymy and spelling corrections), available at the USDA APHIS PPQ Scientific Services Website (https://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/weedlist.pdf). Official government documents should be consulted for the most current information.   For the purpose of the TDC, federal noxious weeds pertain only to those plants listed as occurring within the BONAP geographic area.  For example, although Sparganium erectum is listed as a federal noxious weed, the expression that occurs within our area is Sparganium erectum ssp. stoloniferum, a native taxon that is rare in several states.  The federally noxious plant is the typical expression of the species (Sparganium erectum ssp. erectum) which is not known to occur within our area.   State-level noxious weeds and seeds Plants that have been targeted for management or control at the state or equivalent level because of their extremely destructive or harmful impacts on the economy or the environment and so designated by law.  These include both noxious weed species and noxious seeds, which are often listed seperately. Certain taxonomic and nomenclatural departures from the original lists were necessary in order to conform with the standards set forth by the TDC.  For the precise listings of plants, laws, and definitions pertaining to noxious weeds (and noxious seeds!), public documents from individual state Departments of Agriculture should be consulted.  For noxious-weed seed listing per state, please refer to USDA Agricultural Marketing Service (2016 list available at https://www.ams.usda.gov/sites/default/files/media/NWS%20List%202016.PDF).  It should be noted that many existing noxious plant lists, and the laws governing them, are often antiquated, imprecise, and generally lack conformity regarding definitions and concepts.  After careful assessment of all of the various lists, it is clear that a major revision is necessary in order to make both state statutes and the noxious weed species included within them more accurate.   Based upon the individual U.S. states that have noxious weed (and noxious seed!) lists available, a total of 1,027 taxa are reported to be noxious somewhere within the U.S.  Although this number may appear to be rather high to some, unfortunately, hundreds of others are as bad or even worse than those listed.  In the southeastern U.S. for example, Aegopodium podagraria, Alliaria petiolata, Microstegium vimineum (save Alabama), and Salvinia molesta are but a few examples of intensively invasive and destructive species found here, none of which is listed as noxious by a single state.  Moreover, some states list entire genera as being noxious regardless of the nativity, e.g., Nevada’s listing of the genus Iris, Ohio’s listing of the genus Vitis.  This  sets a rather dangerous precedent, one that needs to be corrected quickly before consequences result.   The fact that certain native species are recognized as invasive should not justify their inclusion on someone’s state noxious weed list, nor should it shock or concern anyone that some native species are invasive. Indeed, many of our native species, e.g. Acer rubrum, Acer barbatum, Liriodendron tulipifera, Pinus taeda, Ulmus alata, Vitis rotundifolia, and countless others are extremely invasive, yet economically and biologically important.  The fact that they are invasive is advantageous to the success of the species and necessary in preventing soil erosion, securing seed germination, and providing the necessary biological stability to our fields, farmlands, and forests.  That they may impact someone’s agricultural lands or gardens should not justify their eradication in natural habitats.   It should be noted that in a few cases, some taxa are listed as noxious by certain states, yet never known to occur there (a policy also adopted by the U.S. federal noxious weed list for the United States, see the definition above).  Apparently, these taxa are listed proactively, to prevent their accidental spread or deliberate planting.  Unfortunately, this too may set a dangerous, untenable, and misleading precedent for reasons too numerous to articulate here.  For the purpose of the TDC, only those taxa currently known to occur within specific states and simultaneously listed as noxious, are included.   Of the 1,027 taxa listed as being noxious by at least one state, the 15 most frequently listed species are as follows:   1.  Cirsium arvense 2.  Convolvulus arvensis 3.  Sorghum halepense 4.  Acroptilon repens 5.  Carduus nutans 6.  Euphorbia esula 7.  Lythrum salicaria 8.  Cardaria draba 9.  Elymus repens 10.  Centaurea biebersteinii 11.  Centaurea diffusa 12.  Lepidium latifolium 13.  Carduus acanthoides 14.  Cyperus esculentus 15.  Cirsium vulgare   Weed Plants that generally grow in disturbed areas or in areas where they are unwanted, often troublesome and unappreciated. Similar to how the exotic Japanese honeysuckle or common dandelion can be viewed as weeds in ones garden, so can seedlings of native species such as northern white oak, American elm, winged elm, sweet gum, or poison ivy. Therefore, within any functional definition of weed, most fundamentally, it should include the words unwanted, troublesome and unappreciated, to underscore the fact that a weed is not a specific plant type, rather a human emotion towards any plant that is unwanted, troublesome or unappreciated, irrespective of its potential usefulness elsewhere.   Invasive  Invasive plant species are exotic plants that have been introduced either intentionally or accidentally into areas outside their native range.  These plants have the potential of causing significant financial damage to croplands and other habitats by establishing large and difficult to control populations, often destroying native plant populations in various habitats and causing losses to cultivated croplands and other environments.