USA: Border States Plant Regulations

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Summary of Approaches

A spreadsheet of 238 plants regulated across Canada and an additional 320 plants regulated in the 13 U.S. States that border Canada (as of July 13, 2023) has been uploaded (it will download when clicked). There are likely errors in this spreadsheet, but links to the primary sources are below and on the Canada: Province & Territories Plant Regulations.

CFR § 360.200 – Designation of noxious weeds. https://www.law.cornell.edu/cfr/text/7/360.200 This law limits the interstate spread of such plants without a permit.

Noxious weed. Any plant or plant product that can directly or indirectly injure or cause damage to crops (including nursery stock or plant products), livestock, poultry, or other interests of agriculture, irrigation, navigation, the natural resources of the United States, the public health, or the environment https://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/weedlist.pdf

APHIS Risk Assessments: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/SA_Weeds/SA_Noxious_Weeds_Program/CT_Riskassessments

2002/137 US draft Federal noxious weed lists EUROPEAN AND MEDITERRANEAN PLANT PROTECTION ORGANIZATION https://gd.eppo.int/media/data/reporting/rs-2002-08-en.pdf

In the absence of an easy tool to search all states Laws & Regulations from the U.S. National Plant Board website has a searchable page with state regulations, including noxious weeds: https://www.nationalplantboard.org/uploads/1/3/6/7/136771235/laws___regulations_search_document.pdf

Alaska AK

AK Invasive Plants and Agricultural Pest Management: https://plants.alaska.gov/invasives/noxious-weeds.htm (Regulations that govern Invasive and Noxious Species come under Title 3: Agriculture, Animals, and Food Chapter under the Commissioners of Natural Resources and Environmental Conservation AS 03.05 010 AS 03.05.030 as well as Title 44. State Government Chapter 37. Department of Natural Resources Section 30. Duties of Department With Respect to Agriculture.AS 44.37.030 11AAC 34.020)

There is a watch for invasive aquatic plants: Myriophyllum aquaticum, M. spicatum, Elodea canadensis, Potamogeton crispus, Phalaris arundinacea, Hydrilla verticillata https://dot.alaska.gov/anc/business/generalAviation/Floatplane-InvasiveSpeciesPrevention.pdf

Idaho ID

ID Laws and rules: Idaho Invasive Species Act of 2008; Idaho Code, Title 22, Chapter 24 – Noxious Weeds. https://invasivespecies.idaho.gov/laws-and-rules ID state prohibited terrestrial plant list: https://invasivespecies.idaho.gov/terrestrial-plants Scientific names listed in the text of the rule: IDAPA 02 – IDAHO DEPARTMENT OF AGRICULTURE Plants Division 02.06.09 – Rules Governing Invasive Species and Noxious Weeds https://adminrules.idaho.gov/rules/current/02/020609.pdf

Idaho Admin. Code r. 02.06.09.220 – NOXIOUS WEEDS – DESIGNATIONS https://www.law.cornell.edu/regulations/idaho/IDAPA-02.06.09.220

IDAPA 02 – IDAHO DEPARTMENT OF AGRICULTURE Plants Division 02.06.09 – Rules Governing Invasive Species and Noxious Weeds https://adminrules.idaho.gov/rules/current/02/020609.pdf

15 aquatic invasive plants – ID State prohibited aquatic plant list https://invasivespecies.idaho.gov/aquatic-plants

“TITLE 22 AGRICULTURE AND HORTICULTURE CHAPTER 19 THE IDAHO INVASIVE SPECIES ACT OF 2008 22-1905. PROHIBITED ACTIONS. No person may import, export, purchase, sell, barter, distribute, propagate, transport or introduce an invasive species into or within the state of Idaho and no person may possess an invasive species, except: …” https://legislature.idaho.gov/statutesrules/idstat/Title22/T22CH19/SECT22-1905/

Maine ME

ME Agriculture CMR 01-001 Chapter 273: Criteria for Listing Invasive Terrestrial Plants. These changes make it illegal to sell, import, export, buy or intentionally propagate for sale the 63 plant species https://www.maine.gov/dacf/php/horticulture/invasiveplants.shtml ; (Pdf of criteria Ch. 273); Criteria for Listing Invasive Terrestrial Plants https://www.maine.gov/sos/cec/rules/01/chaps01.htm )

11 Aquatic plants are prohibited in the aquarium trade https://www.maine.gov/dep/water/invasives/invaquarium.html

ME Title 38: WATERS AND NAVIGATION Chapter 3: PROTECTION AND IMPROVEMENT OF WATERS Subchapter 1: ENVIRONMENTAL PROTECTION BOARD Article 2: POLLUTION CONTROL §419-C. Prevention of the spread of invasive aquatic plants 1. Prohibition. A person may not: A. Transport any aquatic plant or parts of any aquatic plant, including roots, rhizomes, stems, leaves or seeds, on the outside of a vehicle, boat, personal watercraft, boat trailer or other equipment on a public road; [PL 1999, c. 722, §2 (NEW).] B. Possess, import, cultivate, transport or distribute any invasive aquatic plant or parts of any invasive aquatic plant, including roots, rhizomes, stems, leaves or seeds, in a manner that could cause the plant to get into any state waters;… https://legislature.maine.gov/statutes/38/title38sec419-C.html

ME Weed Seed Title 7: AGRICULTURE AND ANIMALS Part 2: MARKETING, GRADING AND LABELING Chapter 103: PRODUCTS CONTROLLED regulates Primary and Secondary Noxious Weeds Seeds. http://www.mainelegislature.org/legis/statutes/7/title7sec1042.html

Michigan MI

Michigan laws regulate the possession and sale of certain plant species which are considered undesirable from agricultural as well as environmental viewpoints. (Natural Resources and Environmental Protection Act Part 413 (Act 451 of 1994), as amended in, 2019, prohibits or restricts specified terrestrial and aquatic plants (https://www.legislature.mi.gov/documents/mcl/pdf/mcl-451-1994-III-2-1-WILDLIFE-CONSERVATION-413.pdf). MI Prohibited and Restricted Weeds https://www.michigan.gov/-/media/Project/Websites/mdard/documents/pesticide-plant-pest/planthealth/michigan_prohibited_and_restricted_weeds.pdf?rev=044acf897d5b432ca34f4b5b2e575657 Noxious weeds are identified in two categories under the Michigan Seed Law (Act 329 of 1965) and Regulations 715 (Under Act 329) Seed Law Implementation. Prohibited noxious weeds – seeds of these species are prohibited as contaminants in seed offered for sale.
Prohibited and Restricted Weeds https://www.michigan.gov/mdard/licensing/agprod/nursery/prohibited-and-restricted-weeds
NATURAL RESOURCES AND ENVIRONMENTAL PROTECTION ACT (EXCERPT) Act 451 of 1994 PART 413 TRANSGENIC AND NONNATIVE ORGANISMS “A person shall not introduce a prohibited species, a restricted species, a genetically engineered or nonnative bird, crustacean, fish, insect, mammal, mollusk, or aquatic plant unless the introduction is authorized by 1 of the following, as applicable:” This act contains lists of regulated species (compiled through 2023) https://www.legislature.mi.gov/documents/mcl/pdf/mcl-451-1994-III-2-1-WILDLIFE-CONSERVATION-413.pdf
Registration required to sell live non-native aquatic plants, under law administered by the Department of Natural Resources (DNR).
Michigan invasive species: Invasive Aquatic Plants – list https://www.michigan.gov/invasives/id-report/plants/aquatic
MICHIGAN LANDOWNER’S GUIDE TO Aquatic Invasive Species Management https://www.michigan.gov/-/media/Project/Websites/invasives/Documents/Action/Guide_AIS_LandownersGuide.pdf?rev=33f1487c3e3943e6880ffb8c3070c366

Minnesota MN

Minnesota combines federal and state lists under various categories. “It is illegal to possess, import, purchase, sell, propagate, transport, or introduce prohibited invasive species, except as allowed by statute” Minnesota and Federal Prohibited Species List 2020: https://files.dnr.state.mn.us/eco/invasives/weedlist.pdf
FN – Federal noxious weed (USDA–Animal Plant Health Inspection Service) – all aquatic plants listed as federal noxious weeds (except Ipomoea aquatica) are also listed as prohibited invasive species by the Minnesota Department of Natural Resources
SN – State noxious weed (Minnesota Department of Agriculture): prevent their spread by prohibiting the importation, sale, and transportation of their propagating parts in the state.
MDA Noxious Weed List Minnesota Statutes 18.75 – 18.91 and 160.23
RN – Restricted noxious weed (Minnesota Department of Agriculture): prevent their spread by prohibiting the importation, sale, and transportation of their propagating parts in the state … Laws and Regulations (Land-based species) https://www.dnr.state.mn.us/invasives/terrestrial/laws.html
PS – State prohibited weed seed (Minnesota Department of Agriculture)

RS – State restricted weed seed (Minnesota Department of Agriculture)

2021 Minnesota Statutes CHAPTER 84D. INVASIVE SPECIES. 84D.05 PROHIBITED INVASIVE SPECIES. Subdivision 1.Prohibited activities. A person may not possess, import, purchase, sell, propagate, transport, or introduce a prohibited invasive species, ..84D.075 NONNATIVE SPECIES, AQUATIC PLANTS, AND AQUATIC MACROPHYTES; PARTS AND LIFE STAGE. A law relating to a nonnative species, aquatic plant, or aquatic macrophyte applies in the same manner to a part of a nonnative species, aquatic plant, or aquatic macrophyte, whether alive or dead, and to any life stage or form. https://www.revisor.mn.gov/statutes/cite/84D Prohibited and Regulated Invasive Species are listed here: https://www.dnr.state.mn.us/invasives/laws.html#prohibited

For explanation of laws and current list of Minnesota prohibited and restricted noxious weeds see MDA Noxious Weed List opens in a new browser tab.  Minnesota Statutes 18.75 – 18.91 opens in a new browser tab and 160.23 opens in a new browser tab.

Minnesota invasive species laws https://www.dnr.state.mn.us/invasives/laws.html#:~:text=an%20appropriate%20classification-,Transportation%20prohibitions,while%20attached%20to%20aquatic%20plants.
2022 Minnesota Statutes CHAPTER 84D. INVASIVE SPECIES https://www.revisor.mn.gov/statutes/cite/84D
Minnesota Administrative Rules CHAPTER 6216, INVASIVE SPECIES https://www.revisor.mn.gov/rules/6216/

Current state law prohibits transportation of all aquatic plants (with a few exceptions).

Under state law, it is unlawful to:

• transport aquatic plants, except as allowed in statutes opens in a new browser tab ($100 civil penalty or misdemeanor)
• place or attempt to place into waters of the state a boat, seaplane, or trailer that has aquatic plants ($200 civil penalty), zebra mussels, or other prohibited invasive species attached ($500 civil penalty or misdemeanor).
  
• Prohibited Aquatic Plants
• African oxygen weed (Lagarosiphon major)
• aquarium watermoss or giant salvinia (Salvinia molesta)
• Australian stone crop (Crassula helmsii)
• brittle naiad (Najas minor)*
• curly-leaf pondweed (Potamogeton crispus)*
• Eurasian watermilfoil (Myriophyllum spicatum)*
• European frog-bit (Hydrocharis morsus-ranae)
• flowering rush (Butomus umbellatus)*
• hydrilla (Hydrilla verticillata)
• Indian swampweed (Hygrophila polysperma)
• purple loosestrife (Lythrum salicaria, Lythrum virgatum, or any variety, hybrid, or cultivar thereof)*
• starry stonewort (Nitellopsis obtusa)*
• water aloe or water soldiers (Stratiotes aloides)
• water chestnut (Trapa natans)
• the aquatic plants listed in Code of Federal Regulations, title 7, section 360.200, are also designated as prohibited invasive species except for Chinese water spinach (Ipomoea aquatica)
• Regulated invasive species
• It is legal to possess, sell, buy, and transport regulated invasive species, but they may not be introduced into a free-living state, such as being released or planted in public waters. The regulated invasive species are:
• Regulated Aquatic plants
• Brazilian waterweed (Egeria densa)
• Carolina fanwort or fanwort (Cabomba caroliniana)
• Chinese water spinach (Ipomoea aquatica)
• nonnative waterlilies (Nymphaea spp.)*
• parrot’s feather (Myriophyllum aquaticum)
• water hyacinth (Eichhornia crassipes)
• yellow iris or yellow flag (Iris pseudacorus)*

Montana MO

MONTANA has a County Weed Control Act and lists several categories of weed plants here: Designation of Noxious Weed Management.

Montana’s Aquatic Invasive Species laws and rules. “It is illegal . . . To move live fish, aquatic plants, or invertebrates from one water body to another without FWP authorization.” https://fwp.mt.gov/conservation/aquatic-invasive-species/rules

Aquatic Invasive Species Laws – establishes a mechanism for Montana to take concerted action to detect, control, and manage invasive species. (80-7-1001 through 1019 MCA)

Aquatic Invasive Species Rules – the prevention, inspection, and decontamination processes for aquatic invasive species in Montana. (ARM Rule 12.5.706)
Montana Aquatic Noxious Weeds Eurasian Watermilfoil ( Myriophyllum spicatum) Flowering Rush ( Butomus umbellatus) Curlyleaf Pondweed ( Potamogeton crispus) https://agr.mt.gov/Topics/N-P/Noxious-Weeds-Pages/Aquatic-Invasive-Species-Program

New Hampshire NH

“In accordance with the Invasive Species Act, HB 1258-FN, the NH Department of Agriculture, Markets & Food, Division of Plant Industry is the lead state agency responsible for the evaluation, publication and development of rules on invasive plant species for the purpose of protecting the health of native species, the environment, commercial agriculture, forest crop production, or human health. The rule, Agr 3800, states “No person shall collect, transport, import, export, move, buy, sell, distribute, propagate or transplant any living and viable portion of any plant species, which includes all of their cultivars and varieties, listed in Table 3800.1, New Hampshire prohibited invasive species list”. https://www.agriculture.nh.gov/publications-forms/documents/prohibited-invasive-species.pdf (CHAPTER 88 HB 1258-FN – FINAL VERSION https://www.chesapeakenetwork.org/wp-content/uploads/2013/11/NH-statute-re-ISC-HB-1258-FN.pdf )

There is now a New Hampshire Comprehensive Invasive Plant List which includes aquatic and terrestrial species as well as species on a watch list. https://www.agriculture.nh.gov/publications-forms/documents/nh-invasive-plant-list.pdf
Section Agr 3802.01 – NH Prohibited Invasive Species https://casetext.com/regulation/new-hampshire-administrative-code/title-agr-commissioner-department-of-agriculture-markets-and-food/chapter-agr-3800-invasive-species/part-agr-3802-nh-prohibited-invasive-species/section-agr-380201-nh-prohibited-invasive-species current through jun 7 2023.
Law Prohibits Exotic Aquatic Plants Since January 1, 1998, the sale, distribution, importation, propagation, transportation and introduction of key exotic aquatic plants has been prohibited (RSA 487:16-a) https://www.des.nh.gov/sites/g/files/ehbemt341/files/documents/2020-01/bb-40.pdf

New York NY

“A regulation (Part 575) was adopted in July 2014, that prohibits or regulates the possession, transport, importation, sale, purchase and introduction of select invasive species. The purpose of this regulation is to help control invasive species, a form of biological pollution, by reducing new infestations and spread of existing populations. This regulation became effective March 10, 2015.” https://www.dec.ny.gov/animals/99141.html
Title 6 Department of Environmental Conservation Part 575 Prohibited and Regulated Invasive Species https://govt.westlaw.com/nycrr/Browse/Home/NewYork/NewYorkCodesRulesandRegulations?guid=Ie8d3e7b0339611e4baa20000845b8d3e&originationContext=documenttoc&transitionType=Default&contextData=(sc.Default)

Noxious Weeds are also regulated by the New York State Department of Agriculture and Markets and are listed in Article 9 of the Agriculture and Markets law Chapter 631 Relating to Inspection and Sale of Seeds with Rules and Regulations (Revised 2003).
575.3 Prohibited invasive species. https://govt.westlaw.com/nycrr/Document/Ia2581e1538fe11e483ae0000845b8d3e?viewType=FullText&originationContext=documenttoc&transitionType=CategoryPageItem&contextData=(sc.Default)&bhcp=1

North Dakota ND

North Dakota Law (NDCC § 4.1-47-02) requires every person to do all things necessary and proper to control the spread of noxious weeds. The North Dakota Department of Agriculture coordinates the efforts of county and city weed boards and state and federal land managers to implement integrated weed management programs. “Noxious weeds cause millions of dollars in damage to North Dakota crops and forage. Many additional dollars are spent in both public and private efforts to control these weeds. In addition to their agronomic impact, noxious weeds adversely affect rural and urban landscapes, tax revenues, recreational opportunities and wildlife habitat.” “Noxious weed” means a plant propagated by either seed or vegetative parts and determined to be injuriousto public health, crops, livestock, land, …4.1-47-02. Control of noxious weeds.1. Each person shall do all things necessary and proper to control the spread of noxious weeds. 2. No person may distribute, sell, or offer for sale within this state a noxious weed.”
NORTH DAKOTA’S NOXIOUS WEED LAW AND REGULATIONS https://www.ndda.nd.gov/divisions/plant-industries/noxious-weeds
North Dakota Noxious Weed Law and Regulations, Agricultural Commissioner – Doug Goehring, 2015: https://www.library.nd.gov/statedocs/AgDept/2015NoxiousWeedsweb20160225.pdf

North Dakota passed its Aquatic Nuisance Species law in 2005. Title 30 Game and Fish Department ANS Administrative Rules (see 30-03-06) Aquatic Species https://gf.nd.gov/gnf/fishing/docs/aquaticnuisance-species-list.pdf Aquatic Nuisance Species Regulations https://gf.nd.gov/ans/regulations#:~:text=ANS%20Regulations,leaving%20a%20body%20of%20water.

Ohio OH

Effective: January 7, 2018 “In order to protect native plant species and thwart the growth of invasive plant species, 38 plants have been declared invasive in Ohio. No person shall sell, offer for sale, propagate, distribute, import or intentionally cause the dissemination of any invasive plant in the state of Ohio” Rule 901:5-30-01 | Invasive plant species. https://codes.ohio.gov/ohio-administrative-code/rule-901:5-30-01
(A) In order to protect native plant species and thwart the growth of invasive plant species, the director of the Ohio department of agriculture pursuant to section 901.50 of the Revised Code hereby declares the plants listed in paragraphs (A)(1) to (A)(38) of this rule as invasive plants. The invasive plants are first designated by the plant’s botanical name and then by the plants common name. The botanical name is the official designation for the plant.”
“Ohio law prohibits the sale of any agricultural, flower, or vegetable seed containing prohibited noxious-weed seeds. The sale of agricultural seed containing more than 0.25 percent by weight of restricted noxious-weed seeds or bulblets, or more than 2.5 percent of all weed seeds, is also prohibited” Ohio Dept. of Agriculture Noxious Weed Seeds (https://agri.ohio.gov/divisions/plant-health/grain-warehouse-feed-and-seed/noxious-weed-seeds
“Ohio law requires counties, townships and municipalities to cut or destroy all noxious weeds, brush, briers, burrs, and vines growing along roads and streets within their jurisdictions. Cutting of the vegetation must occur every year between June 1 and 20, August 1 and 20, and if necessary, September 1 and 20, or whenever it’s necessary to destroy the vegetation to prevent or eliminate a safety hazard. Ohio Revised Code (O.R.C.) §§ 5579.04 and 5579.08.” https://farmoffice.osu.edu/sites/aglaw/files/site-library/NoxiousWeedLawBulletin.pdf

(Applicable code for management: Section 5579.04 | Destruction of brush, briers, weeds, and thistles along highways. Section 5579.05 | Notice to destroy weeds. Section 5579.08 | Cutting of briers, brush, and noxious weeds. )

Rule 901:5-37-01 | Prohibited noxious weeds. Ohio Administrative Code /901:5 /Chapter 901:5-37 | Noxious Weeds https://codes.ohio.gov/ohio-administrative-code/rule-901:5-37-01
Removal of noxious weeds is complaint driven Section 5579.05 | Notice to destroy weeds. Ohio Revised Code /Title 55 Roads-Highways-Bridges /Chapter 5579 General Highway Provisions https://codes.ohio.gov/ohio-revised-code/section-5579.05

Pennsylvania PA

Noxious weeds are identified as a plant that is determined to be injurious to public health, crops, livestock, agricultural land or other property and cannot be sold, transported, planted, or otherwise propagated in Pennsylvania. Weeds are placed within one of three classes, Class A, B, or C based on spread and eradication potential and includes the the Federal Noxious Weed list by default as Class C weeds.  Class C is an interesting category as it includes plants “not known to exist in Pennsylvania but pose a potential threat if introduced and those listed on the Federal Noxious Weed List.”
“No person may research, market, distribute, transport, cultivate, hold, retail, wholesale, propagate or display a noxious weed or controlled plant without obtaining a permit from the department in accordance with the provisions of this chapter” (AGRICULTURE CODE (3 PA.C.S.) – CONTROLLED PLANTS AND NOXIOUS WEEDS Act of Oct. 30, 2017, P.L. 774, No. 46)
Controlled Plant List:
https://www.agriculture.pa.gov/Plants_Land_Water/PlantIndustry/NIPPP/Pages/Controlled-Plant-Noxious-Weed.aspx

Invasive plants management by the Pennsylvania Dept. of Conservation and Natural Resources – DCNR has deemed these trees, shrubs, vines, herbs, and aquatic plants to be invasive on state lands. The species listed are managed by DCNR staff https://www.dcnr.pa.gov/Conservation/WildPlants/InvasivePlants/InvasivePlantFactSheets/Pages/default.aspx

Vermont VT

This rule established by the Agency of Agriculture, Food and Markets under the authority granted to the secretary at 6 V.S.A., Chapter 84, ‘Pest Survey, Detection and Management’, and 6 V.S.A., § 1 (a) (10) prohibits the movement, sale, possession, cultivation, and / or distribution plant material classified as a noxious weed.
“Class A Noxious Weed” means any noxious weed that is not native to the State, not currently known to occur in the State on the date of listing, and poses a serious threat to the State.”Class B Noxious Weed” means any noxious weed that is not native to the state, is of limited distribution statewide, and poses a serious threat to the State, or any other designated noxious weed being managed to reduce its occurrence and impact in the State, including those on the Federal Noxious Weed List (7 C.F.R. 360.200).
“This rule prohibits the sale, movement, distribution, and in some cases, possession or cultivation of certain species of plants that have been recognized as invasive in Vermont or adjacent States. The impacts of these plant species on native ecosystems outweigh their value as ornamental plants in the nursery and landscaping trades to the extent that the Agency of Agriculture has banned their sale in an effort to prevent their introduction into as yet uninfested areas, or slow their further spread across the state through commerce.
This rule does not prohibit the possession or cultivation of so called Class B plants already established in ornamental or landscape plantings, and there is no requirement or obligation of landowners or managers to remove B plants where they are already growing. Possession, cultivation, sale, movement, and distribution of Class A plants is prohibited.” https://agriculture.vermont.gov/sites/agriculture/files/documents/PHARM/Plant_Pest/Amended_Weed_Rule_NoxWeedsFaq.pdf
They are listed as: a) Aquatic and Wetland Weeds; b) Parasitic weeds; (c) Terrestrial weeds:
https://agriculture.vermont.gov/sites/agriculture/files/documents/PHARM/Plant_Pest/NoxiousWeedsQuarantine1.pdf

Transport of Aquatic Plant and Animal Species (10  V.S.A. § 1454) “A person shall not transport an aquatic plant, aquatic plant part, or aquatic nuisance species to or from any Vermont water.” https://dec.vermont.gov/watershed/lakes-ponds/aquatic-invasives/laws-and-regs

Washington WA

RCW 17.10 (Revised Code of Washington) is the state’s basic weed law. WAC Chapter 16-750 includes the state Noxious Weed List. The State’s Noxious Weed List is Organized into Three Classes of Weeds: Class A, B, and C. All Class A Noxious Weeds and many Class B and C noxious weeds are on the Quarantine List.
“It is illegal to transport, buy, sell, or trade any quarantined species. It is also illegal to distribute seed packets, flower seed blends, or ‘wildflower mixes’ that include these plants. Anyone who violates the quarantine restrictions is subject to a civil penalty of up to $5,000 per violation.”
https://www.nwcb.wa.gov/washingtons-noxious-weed-laws
Quarantine List https://www.nwcb.wa.gov/noxious-weed-quarantine-list

Class A = Non-native species that are limited in distribution in Washington. State law requires that these weeds be eradicated.Class B = Non-native species that are either absent from or limited in distribution in some portions of the state but very abundant in other areas. The goals are to contain the plants where they are already widespread and prevent their spread into new areas.Class C = Non-native plants that are already widespread. Counties can choose to enforce control, or they can educate residents about controlling these noxious weeds.
Washington https://cms.agr.wa.gov/getmedia/9e83eb5b-8131-48a9-9066-aa76f077a219/brochureprohibitedplants.pdf

Pacific Northwest Noxious Weed List https://depts.washington.edu/waipc/pnwnoxiousweedlist.shtml (Compares states and provinces)

Wisconsin WI

The invasive species rule, Wis. Admin. Code NR 40 identifies, classifies, and controls invasive species. Regulation includes the movement of invasive plants or their seeds, either intentionally through planting or unintentionally. The list: https://dnr.wi.gov/topic/invasives/documents/NR40plantlist.pdf The law: https://docs.legis.wisconsin.gov/code/admin_code/nr/001/40.pdf

The invasive species rule creates a comprehensive, science-based system with criteria to classify invasive species into two categories: “prohibited” and “restricted.” With certain exceptions, the transport, possession, transfer and introduction of prohibited species is banned. https://dnr.wisconsin.gov/topic/invasives/classification.html
https://p.widencdn.net/xy4gp3/SS1160

Restricted species are also subject to a ban on transport, transfer and introduction, but possession is allowed https://dnr.wisconsin.gov/topic/invasives/classification.html
List https://dnr.wi.gov/topic/Invasives/documents/nr40lists.pdf

“Noxious weed” means Canada thistle, leafy spurge, field bindweed, any weed designated as a noxious weed by the department of natural resources by rule, and any other weed the governing body of any municipality or the county board of any county by ordinance or resolution declares to be noxious within its respective boundaries.” (66.0407 Noxious weeds.)

Regulated Aquatic Invasive Plants in WI https://www3.uwsp.edu/cnr-ap/UWEXLakes/Documents/programs/CBCW/publications/WT-960.pdf
 Eurasian water milfoil, curly leaf pondweed and purple loosestrife are mentioned in Chapter NR 109 AQUATIC PLANTS: INTRODUCTION, MANUAL REMOVAL AND MECHANICAL CONTROL REGULATIONS https://docs.legis.wisconsin.gov/code/admin_code/nr/100/109/07/2
No person may distribute an invasive aquatic plant, under s. NR 109.07.