Missouri Invasive Plant Council (MoIP) - to identify and control invasive plants

2021 Top 25 Invasive Plants Expanding in Missouri

by Tina Casagrand

The Missouri Invasive Plant Task Force’s (MoIP) 2021 List of Expanding Invasive Plants draws data from MoIP’s statewide assessment that was compiled and reviewed by experienced field biologists in Missouri. In addition to identifying invasive plant abundance and assessing the severity of the plants’ impact on natural communities, biologists estimated how rapidly the species’ ranges will expand to form new occurrences throughout each of Missouri’s primary ecological regions over the next 10 years. The results follow here.

Because of their vigorous expansion, the species on the 2021 Top Invasive Plants Expanding in Missouri list are particularly important to identify and control. See below for links to resources on how to identify and control each plant.

Click to download the 2021 MoIP flier listing top 25 expanding invasive plants in Missouri.

This assessment will be updated every several years based on additional and ongoing in-the-field observations and reviews.

1. Callery pear

Pyrus calleryana

Representative photos of Callery pear:

2. Garlic mustard

Alliaria petiolata

Representative photos of garlic mustard:

3. Sericea lespedeza

Lespedeza cuneata

Representative photos of Sericea lespedeza:

4. Invasive privets

Ligustrum spp.

Representative photos of some invasive privets:

5. Reed canary grass

Phalaris arundinacea

Representative photos of reed canary grass:

6. Japanese stiltgrass

Microstegium vimineum

Representative photos of Japanese stiltgrass:

7. Invasive bush-honeysuckles

Lonicera spp.

Representative photos of invasive bush-honeysuckles:

8. Himalayan blackberry

Rubus armeniacus

Representative photos of Himalayan blackberry:

9. Autumn olive

Elaeagnus umbellata

Representative photos of autumn olive:

10. Japanese chaff flower

Achyranthes japonica

Representative photos of Japanese chaff flower:

11. Japanese honeysuckle

Lonicera japonica

Representative photos of Japanese honeysuckle:

12. Japanese hops

Humulus japonicus

Representative photos of Japanese hops:

13. Wintercreeper, climbing euonymus

Euonymus fortunei

Representative photos of wintercreeper:

14. Teasels

Dipsacus spp.

Representative photos of teasels:

15. Sweet autumn virginsbower

Clematis terniflora

Representative photos of Sweet autumn virginsbower:

16. Smooth brome

Bromus inermis

Representative photos of smooth brome:

17. Invasive wisterias

Wisteria floribunda and Wisteria sinensis

Representative photos of invasive wisterias:

18. Oriental bittersweet

Celastrus orbiculatus

Representative photos of Oriental bittersweet:

19. Spotted knapweed

Centaurea stoebe subsp. micranthos

Representative photos of spotted knapweed:

20. Japanese knotweed

Fallopia japonica

Representative photos of Japanese knotweed:

21. Burning bush

Euonymus alatus

Representative photos of burning bush:

22. Birdsfoot trefoil

Lotus corniculatus

Representative photos of birdsfoot trefoil:

23. Johnson grass

Sorghum halepense

Representative photos of Johnson grass:

24. Old-world bluestems

Bothriochloa spp.

Representative photos of old-world bluestems:

25. Common reed

Phragmites australis

Representative photos of common reed:

Why some common invasive plants did not make this particular list

Plants listed above may be expanding rapidly in some Missouri regions, but not in others.

Some readers may be surprised to see that some commonly known invasive plants, such as multiflora rose (Rosa multiflora) or ground ivy/creeping charlie (Glechoma hederacea) are not listed. That is because this “Top 25” list emphasizes expansion of range/abundance. According to the assessment, multiflora rose shows only a “Gradual Increase” in all regions with sufficient data. That resulted in multiflora rose scoring much lower on this list than many other species that show more vigorous expansion.

Do you have an observation to share?

You may report observations of invasive plants in your area any time using the Mapping MO Invasives app or EDDMapS Midwest. These real-time mapping systems for documenting invasive species distribution are fast, easy to use and important for early detection and rapid response to invasive species before they become unmanageable problems.

State verifiers review all data to ensure accuracy. The data are made freely available to scientists, researchers, land managers, land owners, educators, conservationists, ecologists, farmers, foresters, state and national parks.