Midwestern Early Detection Plant Species

A regional early detection species is one that is either a) not yet present in the Midwest, but is prevalent and spreading in neighboring regions, or b) present in the Midwest in relatively small or isolated populations with high risk of further spread.

In the Fall of 2022, MIPN issued a survey to invasive plants experts across our region of Iowa, Illinois, Indiana, Kentucky, Michigan, Minnesota, Missouri, Ohio, Ontario, and Wisconsin. We asked them to identify early detection species for the Midwest region. We received a total of 65 responses from across the entire MIPN region. The ten most frequently reported species are highlighted below, along with information about which species are of greatest concern to each individual state/province.

We encourage people who spend a lot of time outdoors to become familiar with early detection species and to report sightings using tools like EDDMapS or MISIN and/or directly to a CISMA/CWMA or other local natural resources authorities. If land managers are made aware of new instances of these species soon after they arrive, they can take action to control and hopefully eradicate these populations before they become large in size. 

Lesser celendine was the most frequently named emerging invasive plant in our survey. (Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org)

Lesser celandine was the most frequently named emerging invasive in our survey  (Photo credit: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org)


Download our Top Ten Emerging Midwest Invasive Plants flyer

These were the most frequently named plant species in order of the number of responses (in parentheses). Plants that were named as emerging invasive plants by all 10 states/provinces are indicated by an asterisk. To see a full list of species named in both our 2020 and 2022 survey, click here. 

  • Lesser celandine - Ficaria verna (15)
  • Japanese stiltgrass* - Microstegium vimineum (13) 
  • Poison hemlock -Conium maculatum (12) 
  • Teasels - Dipsacus spp. (11) 
  • Japanese hops - Humulus japonicus (8) 
  • Japanese chaff flower - Achyranthes japonica (8) 
  • Mile-a-minute weed* - Persicaria perfoliata (7)
  • Porcelain berry* -Ampelopsis brevipedunculata (7)
  • Black and Pale Swallow-worts* - Cynanchum louiseae and Cynanchum rossicum (7) 
  • Amur cork tree - Phellodendron amurense (7)


Listed below are the plants that were named the greatest concern for each state/province. In the case of an even number of responses, more than one species is listed:

Indiana:  Lesser celandine - Ficaria verna, Japanese chaff flower - Achyranthes japonica, Swallow-worts - Cynanchum spp.
Illinois: Lesser celandine - Ficaria verna, Japanese stilt grass - Microstegium vimineum
Iowa: Japanese hops - Humulus japonicus
Kentucky: Lesser celandine - Ficaria verna, Japanese chaff flower - Achyranthes japonica
Michigan: Japanese stilt grass - Microstegium vimineum
Minnesota: Teasels - Dipsacus spp., Japanese hops - Humulus japonicus
Missouri: Lesser celandine - Ficaria verna
Ohio: Japanese chaff flower - Achyranthes japonica
Ontario: Mile-a-minute weed - Persicaria perfoliata
Wisconsin: Lesser celandine - Ficaria verna, Japanese stilt grass - Microstegium vimineum, Swallow-worts - Cynanchum spp.

A similar survey was completed in 2020. MIPN staff worked with colleagues at Minnesota Department of Agriculture, Wisconsin Department of Natural Resources, and Johnson County, Iowa to survey natural resource practitioners in surrounding states about the terrestrial invasive plant species they are perceive as relatively new and rapidly spreading. Those results are summarized here

State agencies and/or invasive plant councils often maintain lists of state-specific priority early detection species, which are linked below. We have also compiled some species-specific resources to help with identification and control recommendations for early detection species. Do you have a resource related to an early detection species that you'd like us to share? Please contact us.

State Early Detection Resources and Priority Lists

Defining early detection species on a regional level can be tricky. It is also valuable for people to know what species are new and spreading in their neck of the woods. State agencies and invasive plant councils are a great resource, as are any local CWMAs. Here are some state-wide resources that we have identified:

  • Indiana Invasive Species Council - New Invasive Plants to Watch For, 2018 (pdf)
  • Michigan Department of Natural Resources - Watch List, 2023 (pdf)
  • Minnesota Departments of Natural Resources and Agriculture - Keep a Lookout, 2017 (pdf)
  • Missouri Invasive Plant Council - Top Invasive Plants in Missouri
  • Ohio Department of Natural Resources - Watch List, 2000 (pdf)
  • Wisconsin Department of Natural Resources - NR-40 List, 2015 (pdf)
    • "Prohibited" and "Prohibited/Restricted" plants can be considered early detection species in WI



Species Specific Resources


(listed by habitat type and alphabetically by Latin name)

Terrestrial Species

Aquatic Species