Idea to Cease the Sale of Some Invasive Plants in Missouri

In 2015, the native plant Grow Native! Program spearheaded the Missouri Invasive Plant Task Force (MoIP), an independently organized multi-discipline group bolstering statewide efforts to identify and control the invasive plant species that severely impact native biodiversity and economies of working lands. MoIP is not a regulatory group.

The purpose of the task force is to review, discuss, and recommend educational and regulatory action related to managing known and potential non-­native invasive plant species that negatively impact natural communities and built landscapes in Missouri and elsewhere in the lower Midwest.

Representatives from the fields of conservation, agriculture, botanical science, ecological services, plant production, horticulture, landscape services and design, and arboriculture make up the task force. They communicate MoIP recommendations with their representative organizations to act as a united, supportive front. 

• See list of MoIP members and stakeholders.
• Download MoIP Fact Sheet

Private property owners, communities, farmers, business owners, industry, and tax-supported state agencies suffer economic losses controlling invasive plants. While many people are exerting effort to control invasive plants on the ground in Missouri, no state statutes exist to stop invasive plants from being sold in the state, beyond the Missouri Noxious Weed Law, which currently prohibits the sale of 12 invasive plants. As we have seen with Callery (Bradford) pear invasion, even plants thought to be sterile are exhibiting significant invasive characteristics in the field.

In an effort to stop any more invasive plant problems before they start, MoIP is proposing an idea for state legislation that would prohibit the sale, known distribution, and propagation of some invasive plants. Many states, including Indiana, Ohio, Maryland, and Tennessee have recently passed legislation of this nature, for the benefit of agricultural, horticultural, silvicultural, and other interests of their states. This proposed legislation would not penalize landowners for presence of invasive plants on their property and would not require them to control these plants.

Many Missourians are familiar with the Missouri Noxious Weed Law, which both:

1. requires property owners to control noxious weeds on their property and 
2. prohibits noxious weeds from being sold

Violation of either of these provisions is subject to penalty by the county prosecutor.

The state designates 12 species of weeds as noxious. Currently, adding a plant to the Noxious Weed Law list requires review and approval by the Missouri Department of Agriculture.

However, to create a new designation of plants that are banned from sale (but neither penalizes property owners for presence of invasive plants, nor requires them to treat or remove those invasive plants) would require changing statutes through the legislative process. For example, Indiana and Ohio recently enacted new state statutes and rules for invasive plants that are separate from their Noxious Weed Laws. 

MoIP's idea for a state statute is different from the Missouri Noxious Weed Law in this significant way: it would not penalize property owners for the presence of a known invasive plant. Such a statute would be complementary to—not a replacement or alteration of—the Noxious Weed Law. 

Voting Body for Inclusion of Species - MoIP recognizes the importance of carefully composing a voting body of experts to determine which species would be included on a proposed state statute limiting the sale, propagation, and intentional distribution of certain invasive plants. The legal authority in charge of implementing any statute would likely determine such a voting body. MoIP is researching compositions of voting bodies similar to those of invasive plant regulation efforts in Illinois or Ohio, both of which specifically are required to include representatives from horticulture, conservation, and academic sectors.

Restrictions - Except as provided below, it is envisioned that under such a statute, a person would not intentionally propagate, import, transfer, sell, purchase, or introduce any viable part of an invasive plant in the State. It is envisioned that these restrictions would not apply to the transfer, lease, sale, or purchase of real property on which an invasive plant is already established.

Phase-Out Periods - Some plants, particularly in the ornamental trade, require multi-year upfront investment before selling to the public. Interested stakeholder groups are invited to recommend a “phase out” period of time during which existing stock of certain invasive plant species may still be legally sold after potential passage of the statute. 

Recommendations for Trade Alternatives MoIP suggests alternative non-invasive plants with which to replace restricted invasive plants in commerce. Many alternative plants exist, including:

• Grow Native!: Alternative Species
• Midwest Invasive Plant Network: Native Landscape Alternatives
• Woody Invasives of the Great Lakes Collaborative: Landscape Alternatives

Exemption Options - MoIP is exploring options for possible exemptions. These may include:

• The activity is for the purpose of: 
• Disposing of the invasive plant
• Controlling the invasive plant
• Using the invasive plant for research or educational purposes
• Commercial and individual floriculture remains - properly discard so viable parts of plant don’t take root or go to seed.

Resources for the Regulating Authority - MoIP’s proposal would also authorize funding and regulatory authority to the appropriate state agency or other entity to manage the statute.

Declassification - MoIP is exploring options for possible declassification protocols.  For example, Maryland allows for declassification with this language: “A person that requests a declassification of a plant ... including cultivars of specific plants presently listed, must submit a written request to the Secretary that includes:

• Name of the Requestor

• Contact Information

• Scientific name of the plant

• Detailed justification of the request”  

Penalties and Enforcement - The legal authority in charge of implementing any statute would determine penalties and enforcement.

One of MoIP's top priorities when it formed in 2015 was to create an updated, comprehensive list of known invasive plants in Missouri. To develop this list, MoIP sought input from experienced Missouri field biologists. Twenty-six professional reviewers assigned independent ranks to 142 invasive plant species for the following three categories:

1. Impact: How severe is the current impact of the species on natural communities in each of Missouri’s primary ecological regions?
2. Current Abundance: Estimate the species current abundance in each of Missouri’s primary ecological regions.
3. Trend in Distribution and Abundance: Based on observations and regional trends over the past 10 to 20 years, estimate how rapidly the species range will expand to form new occurrences throughout each of Missouri’s primary ecological regions over the next 10 years?

The results are freely available on moinvasives.org. 

• Rankings are displayed through regional maps accessible as a searchable table or downloadable via Dropbox. 
• Some species display blank maps because of insufficient review data to populate the map. The ‘insufficient data’ tag in the maps means that there were fewer than 3 reviews for that species/region. There is also a ‘no data’ tag for those without any reviews. Even though some maps show insufficient data for certain plants, they are included in the assessment list of 142 plants because they are known as invasive and/or are regulated in neighboring states.
• Download all raw data for the Missouri Invasive Plant Assessment here (locked)

This assessment has been helpful in determining species of concern that have already established a presence in Missouri, and helps natural resource professionals plan control efforts. MoIP is inviting stakeholder groups to review this list of 142 plants as part of its process for determining a list of some invasive plants to include on a potential statue. Each plant on our list was assessed for review due to data from other regional states and inclusion on invasive.org and other reputable resources.

MoIP is inviting more than 90 groups in late 2020/early 2021 to review and provide feedback on which of the plants on the list of 142 plants they would support including on a cease-the-sale list and which ones they would oppose including on a cease-the-sale list. MoIP is providing reviewers with detailed instructions.

See FAQ for a list of the invited reviewer groups.

Science Phase

• 2016: Research for the Missouri Invasive Plant Assessment begins compiling extensive research on known and potentially invasive plants, a process that took approximately 75 hours to complete.
• 2017: Starting with our network of local, state and federal agencies and private industries, MoIP sought input from experienced field biologists in Missouri. MoIP received 26 completed reviews.
• 2018: Data/metrics documented and converted into regional maps.
• February 2019: Impact analysis/mapping shared online and in presentations, such as to the Missouri Natural Resources Conference

Stakeholder Engagement Phase

• Winter 2019/2020: MoIP begins gathering reviewer groups/principal contact identification. MoIP begins developing documentation and input tool for review.
• Establish composition of a review committee for review of stakeholder input
• Spring 2020: MoIP begins develop a matrix for summarizing stakeholder input.
• April 7, 2020: (cancelled due to COVID-19) MoIP invites stakeholders to statewide meeting on invasive plant topics
• September 2020: introduce idea for statute to general public via a Grow Native! webinar (see recording)
• As of early December 2020, MoIP is reviewing initial feedback to determine its next steps regarding stakeholder input/comment/advisement
• late 2020/early 2021: Request for stakeholder input/comment/advisement

Legislative Advocacy/Engagement Phase

• Stakeholder input will determine whether MoIP will advance to this stage or not.

This is a list of 142 species deemed to be invasive by MoIP. Their rates of invasiveness vary. To view maps associated with this ranked assessment of 142 species, click here.

MoIP is inviting approximately 90 stakeholder groups to rate these for what should be included in a proposed cease-the-sale list.

A subset of these plants are sold in farm stores, garden centers, and home improvement stores. Nearly all are available for purchase via the internet.

To re-emphasize, MoIP neither expects nor intends to prohibit sale of all these species. See Section 4 for more information on the process for adding and subtracting plants from the list.

^ Species with this symbol following their names are currently regulated under the Missouri Noxious Weed Law

*While asterix indicate plants that are currently available from traditional retail and wholesale outlets (as assessed by MoIP members associated with the horticultural trade), it is likely any of these plants can be obtained through eBay or other nonconventional retail methods.

Common Name	Scientific Name	Currently available from traditional retail and wholesale outlets.*
air potato	Dioscorea polystachya
amur corktree	Phellodendron amurense
Amur honeysuckle	Lonicera maackii
Amur maple	Acer tataricum	Yes
Amur privet	Ligustrum amurense	Yes
autumn olive	Elaeagnus umbellata	Yes
beefsteak plant, Perilla mint	Perilla frutescens	Yes
bicolor lespedeza	Lespedeza bicolor
birdsfoot trefoil	Lotus corniculatus	Yes
black swallow-wort	Cynanchum louiseae
blackberry lily	Belamcanda chinensis	Yes
border privet	Ligustrum obtusifolium	Yes
Brazilian waterweed	Egeria densa
brittle naiad	Najas minor
bromegrass	Bromus sterilis	Yes
bull thistle	Cirsium vulgare
burdock	Arctium minus
California privet	Ligustrum ovalifolium	Yes
Canada thistle^	Cirsium arvense^
Caucasian bluestem	Bothriochloa bladhii
cheat grass	Bromus tectorum
Chinese chestnut	Castanea mollissima	Yes
Chinese privet	Ligustrum sinense	Yes
Chinese wisteria	Wisteria sinensis	Yes
chocolate vine	Akebia quinata	Yes
climbing euonymus	Euonymus fortunei	Yes
common buckthorn	Rhamnus cathartica
common periwinkle	Vinca minor	Yes
common reed	Phragmites australis
common tansy	Tanacetum vulgare
common teasel^	Dipsacus fullonum^
crown vetch	Securigera varia	Yes
curly leaf pondweed	Potamogeton crispus
cut-leaf teasel^	Dipsacus laciniatus^
Dahurian buckthorn	Rhamnus davurica
dame's rocket	Hesperis matronalis	Yes
dwarf honeysuckle	Lonicera xylosteum	Yes
English ivy	Hedera helix	Yes
Eurasian watermilfoil	Myriophyllum spicatum
European cranberry bush	Viburnum opulus	Yes
European privet	Ligustrum vulgare	Yes
European wand loosestrife	Lythrum virgatum	Yes
field bindweed^	Convolvulus arvensis^
field sowthistle	Sonchus arvensis
fountain grass^	Cenchrus purpurascens^	Yes
garlic mustard	Alliaria petiolata
giant hogweed	Heracleum mantegazzianum
giant Miscanthus	Miscanthus	Yes
giant reed	Arundo donax	Yes
glossy buckthorn, European alder buckthorn	Frangula alnus	Yes
glossy privet	Ligustrum lucidum	Yes
golden bamboo	Phyllostachys aurea	Yes
golden rain tree	Koelreuteria paniculata	Yes
ground ivy, creeping charlie	Glechoma hederacea	Yes
hardheads	Acroptilon repens
heavenly bamboo	Nandina domestica	Yes
Himalayan blackberry	Rubus armeniacus
hydrilla	Hydrilla verticillata
Japanese angelica tree	Aralia elata	Yes
Japanese barberry	Berberis thunbergii	Yes
Japanese chaff flower	Achyranthes japonica
Japanese clover	Kummerowia striata	Yes
Japanese honeysuckle	Lonicera japonica	Yes
Japanese hops	Humulus japonicus
Japanese knotweed	Fallopia japonica
Japanese plume grass	Miscanthus sinensis	Yes
Japanese privet	Ligustrum japonicum	Yes
Japanese stiltgrass	Microstegium vimineum
Japanese wisteria	Wisteria floribunda	Yes
Japanese zelkova, Japanese elm	Zelkova serrata	Yes
jetbead	Rhodotypos scandens	Yes
Johnson grass^	Sorghum halepense^
Korean clover	Kummerowia stipulacea	Yes
kudzu^	Pueraria montana^
Lacebark elm, Chinese elm	Ulmus parvifolia	Yes
leafy spurge	Euphorbia esula
lesser celandine	Ranunculus ficaria
mahaleb cherry	Prunus mahaleb
mile-a-minute weed	Persicaria perfoliata
moneywort, creeping jenny, herb twopence and twopenny grass	Lysimachia nummularia	Yes
Morrow's honeysuckle	Lonicera morrowii
multiflora rose^	Rosa multiflora^
musk thistle^	Carduus nutans^
narrowleaf bittercress	Cardamine impatiens
Norway maple	Acer platanoides	Yes
orange daylily, tawny daylily	Hemerocallis fulva	Yes
Oriental bittersweet	Celastrus orbiculatus	Yes
ornamental pear, callery pear	Pyrus calleryana	Yes
paper mulberry	Broussonetia papyrifera
parrotfeather	Myriophyllum aquaticum
pepperweed	Lepidium latifolium
pincushion flower	Scabiosa atropurpurea	Yes
poison hemlock	Conium maculatum
porcelain berry	Ampelopsis brevipedunculata	Yes
princess tree	Paulownia tomentosa	Yes
purple loosestrife^	Lythrum salicaria^	Yes
ravennagrass	Saccharum ravennae	Yes
reed canary grass	Phalaris arundinacea	Yes
Russian olive	Elaeagnus angustifolia	Yes
saltcedar	Tamarix chinensis	Yes
saw tooth oak	Quercus acutissima	Yes
Scotch thistle^	Onopordum acanthium^
sericea lespedeza	Lespedeza cuneata	Yes
Siberian elm	Ulmus pumila	Yes
silktree	Albizia julibrissin	Yes
silver poplar	Populus alba	Yes
smooth brome	Bromus inermis	Yes
spotted knapweed^	Centaurea stoebe^
star of Bethlehem	Ornithogalum umbellatum	Yes
sweet autumn virginsbower	Clematis terniflora	Yes
sweet breath of spring	Lonicera fragrantissima	Yes
tall fescue	Festuca arundinacea	Yes
Tartarian bush honeysuckle	Lonicera tatarica
tree-of-heaven	Ailanthus altissima	Yes
viper's bugloss	Echium vulgare	Yes
water hyacinth	Eichhornia crassipes	Yes
waxyleaf privet	Ligustrum quihoui	Yes
weeping lovegrass	Eragrostis curvula	Yes
white mulberry	Morus alba	Yes
white sweet clover	Melilotus albus	Yes
wild parsnip	Pastinaca sativa
wine raspberry	Rubus phoenicolasius
winged burning bush	Euonymus alatus	Yes
winter vetch	Vicia villosa	Yes
yellow bluestem	Bothriochloa ischaemum
yellow flag iris	Iris pseudacorus	Yes
yellow star thistle	Centaurea solstitialis
yellow sweet clover	Melilotus officinalis	Yes

1. See photos of escaped cultivation here.
2. See this detailed spreadsheet of Missouri Invasive Plant Assessment for all the raw data that went into the development of the ranked assessment. Columns N through AJ show all other national, state, and regional noxious weed listings for each species.”  

MoIP is inviting the following stakeholder groups in late 2020/early 2021 to provide feedback on MoIP's science-based list of 142 species. MoIP is providing them with detailed instructions.

After MoIP members review the first phase of feedback from these groups, members will revise the cease-the-sale idea. Size and stake of each organization will be considered when evaluating responses.

4-H

AgriMissouri

American Society of Landscape Architects

Association of Missouri Electric Cooperatives

Boy Scouts

Bridging the Gap

Cattlemen's Association

Conservation Federation of Missouri

Farm Service Agency

Federated Garden Clubs

Forest & Woodland Association of Missouri

Future Farmers of America

Garden Centers of America

Gateway Professional Horticultural Association

Girl Scouts - contacted through online form

Great Missouri Birding Trail

Great Rivers Greenway District

Greenhouse Growers Association

L-A-D Foundation

Landscape and Nursery Association of Greater St. Louis

Leave No Trace - contacted through online form

Lincoln Coop Extension

Magnificent Missouri

MFA Incorporated

Missouri Agribusiness Association

Missouri Agriculture Stewardship Assurance Program

Missouri Aquarium Society

Missouri Aquarium Society

Missouri Association of Counties - contacted through online form

Missouri Association of Soil & Water Conservation Districts

Missouri Beef Industry Council

Missouri Botanical Garden

Missouri Coalition for the Environment

Missouri Community Forestry Council

Missouri Consulting Foresters Association

Missouri Corn Growers Association

Missouri Cottongrower's Association

Missouri Crop Improvement Assocation

Missouri Dairy Association

Missouri Department of Conservation

Missouri Dept. of Agriculture

Missouri Dept. of Natural Resources

Missouri Energy Initiative

Missouri Farm Bureau Federation

Missouri Farmers Care

Missouri Farmers Union

Missouri Forage and Grasslands Council

Missouri Forest Products Association

Missouri Green Industry Alliance

Missouri Hemp Association

Missouri Homebuilders Association

Missouri Horse Council

Missouri Master Gardeners

Missouri Master Naturalists

Missouri Medical Cannabis Trade Association

Missouri Municipal League

Missouri Native Seed Association

Missouri Nut Growers Association

Missouri Organic Association

Missouri Park & Recreation Association

Missouri Parks Association

Missouri Pork Association

Missouri Prairie Foundation/GN

Missouri Realtors Association

Missouri Rice Council - contacted through online form

Missouri Right of Way Association

Missouri River Relief

Missouri Seedsmen’s Association

Missouri Solar Energy Industries Association

Missouri Soybean Merchandising Council

Missouri State Arboretum

Missouri State Beekeepers Association

University of Missouri Center for Agroforestry

Missouri Wine & Grape Board

Missouri Women in Agriculture

MO Environmental Education Association

MoDOT

MU Extension

National Forest Service

National Guard

National Park Service

National Wild Turkey Federation

NRCS

Poultry Federation

Powell Gardens

Quail and Upland Wildlife Federation

Quail/Pheasants Forever

Science Teachers of Missouri

Show-Me Farm Safety

Sierra Club

St. Louis Arborists

Stream Teams United

The Nature Conservancy

TPI (turfgrowers group)

Trout Unlimited

U.S. Fish and Wildlife Service

USDA Farm Service Agency

Yes, MoIP is inviting groups to self-report the size of their membership, economic stake in invasive plants, and other considerations. Size and stake of each organization will be considered when evaluating responses. We welcome stakeholder feedback.

No, MoIP is not a regulatory entity. It is a group of people with exceptional professional experience with invasive plants.

Since 2015 MoIP has engaged in numerous outreach opportunities promoting education on the problems, identification, control of invasive plants in Missouri. Our research has found that, while many businesses adapt to knowledge about the impact of invasive plants, some businesses continue to sell known invasive plants as long as the market demands it. This is creating undue burdens on the finances of private landowners and public agencies that spend valuable resources controlling invasive plants that continue to be sold. Stakeholder input will determine whether MoIP will advance to the legislative stage or not.

The idea to cease the sale of known invasive plants in order to slow the spread of invasive plants is by no means unique to MoIP. Any group, individual, or legislator could take up this effort independent of MoIP, and any of these entities may do so with or without inviting groups to provide input.

It is too early in the process to know what the final list will look like. The list will be shaped by the input we receive from stakeholder organizations, as well as affected individuals and businesses during the next phase of feedback.

If and when this effort results in legislation, MoIP foresees asking for a letter of support from all the organizations to present to interested legislators along with the final proposal. MoIP is not taking any input provided at this stage as defacto approval/disapproval of any later full list or other product of the CtS effort. Supportive comments and ratings now could potentially be used as support and/or justification for certain species that may end up on a final list, but those comments would be associated with the species, and not the final list in general.