A New WeedWise Publication The WeedWise Program is pleased to announce a new publication entitled, Woody Weeds of Clackamas County. This resource guide is intended for use by local landowners and land managers to help them identify and manage woody weeds and naturalizing plants on their property. The Woody Weeds of Clackamas County covers a […]
It isn’t everyday that a weed manager feels the need to trade in their work boots for a day spent surrounded by home decor and scented candles. Remarkably, such was the case this week for WeedWise program manager Sam Leininger. Early in the week Sam was alerted to the possibility that a national retailer, Pier […]
Since 2016, the WeedWise program has been working to control the largest known infestation of goatsrue (Galega officinalis) in Oregon. Goatsrue is an Oregon class A noxious weed and has been deemed a high priority for control and eradication because it is toxic to livestock and spreads easily. This federal and state noxious weed is only known at a handful of other sites across Oregon and the Pacific Northwest.
Goatsrue flowers
Goatsrue is a deep-rooted perennial, with hollow stems and compound alternate leaves. The compound leaves have a terminal leaflet and 6-10 pairs of leaflets. The tip of each leaflet rapidly narrows to a fine tip. Goatsrue has pea-like flowers that vary in color from purple to white. Flowers bloom from June to October and are clustered at the end of its branches or at the leaf axils. Unlike some other members of the pea family, goatsrue lacks tendrils and grows in a more upright and bushy form rather than as a vine. The seeds are contained in pods with up to 9 mustard-colored, oblong seeds. Each plant can produce 15,000 pods a year. Additionally, these seeds may remain viable for 5-10 years in the soil.
Goatsrue closely resembles some regionally rare native plants, so we encourage landowners to contact us if they think they may have goatsrue on their property.
Robust goatsrue growth
In May of 2016, during one of our planned weed surveys, one of our contracted survey crews discovered a large previously unknown population of goatsrue on two adjacent riparian properties along the Clackamas River. This infestation affects 14 acres and is the largest known infestation of goatsrue in Oregon. At that time, we began a management effort to contain and control this priority weed with the goal of eradication of the goatsrue as well as several other priority invasive plants present at these sites.
This discovery was found as part of extensive surveys of streamside properties along the Clackamas River initiated in 2015 and continuing into the present. Twenty-one priority invasive plant species were on our target list for these surveys. Some of these species had been documented in our region and some had not. These surveys help us to address new priority invasive plants and better manage priority invasive plants established here. We thank private landowners for allowing us to access their properties for these surveys!
Goatsrue herbicide application
The WeedWise Program initiated control soon after detection of this large infestation. Our approach began confirming the identity of the goatsrue. We then followed up with a thorough review of the biology and control of goatsrue. Most notably, we learned that goatsrue can have a long seed dormancy period allowing seeds to grow after 10 years in the soil. As a perennial weed with a deep taproot, it is all difficult to remove by hand. Therefore, our management goals were to prevent all seed production and to target the large root systems of existing plants.
Next, we researched management strategies appropriate for this plant and this site. We also consulted with the Oregon Department of Agriculture Noxious Weed Control Program and the City of Portland Bureau of Environmental Services who both have prior experience managing goatsrue. Based on this research, we selected two herbicides to treat the infestation: one to target upland populations and a second aquatically approved herbicide to treat infestations that occur near water. The herbicide applications were planned by the WeedWise program and implemented using licensed restoration contractors.
What’s Next?To date, our management efforts have been highly successful, but with the size and complexity of the site we did note some patches with regrowth after herbicide application, as well as new seedlings emerging. On follow-up monitoring of the site, we also found several overlooked patches that had grown in an among other vegetation. In response, our current efforts focus on continuing to scout for missed populations and to remove interspersed invasive Himalayan blackberry (Rubus bifrons) stands which may obscure goatsrue plants. We are carrying out multiple rounds of control each year to ensure that we are not letting any plants go to seed and to continue to address regrowth.
After two years of intensive control, we have dramatically reduced the populations and are on track to eradicate this population. Eradication will require ongoing monitoring and control to address the long seed dormancy. Although we won’t be walking away from the site anytime soon, we are optimistic knowing that the population is significantly reduced, and that we are committed to eradicating goatsrue from Clackamas County!
Do you think you’ve found a noxious weed? Here is how you can get help to identify and report your find! One of the most important aspects in controlling invasive weeds is to verify the identification if invasive weeds before you work to control them. Knowing the difference between an aggressive weed and a common […]
Our first 2017 weed of the month is ivy! You’ve probably seen it carpeting the ground in a natural area, or perhaps completely covering a wall, or possibly climbing high up a tree. Like many invasive plants, it was introduced as an attractive ornamental plant for landscaping. However, it escaped! Ivy has become highly invasive […]
Deck the Halls with Boughs of Holly! December is the month when our busy lives get busier. The December mad dash of shopping, baking, wrapping, and mailing, ultimately gives way to the holidays spent surrounded by our loved ones. December should be a time of enjoying each others company, not concerning ourselves with weeds. After […]
Garden loosestrife (Lysimachia vulgaris) is one of the most recent additions to Oregon’s noxious weed list. As a class A noxious weed, the goal of land managers is to rapidly control infestations before they have a chance to gains a foothold. One critical component of this is approach is to increase awareness of this new […]
The old adage “many hands make light work” could not be truer when it comes to weed management. The WeedWise Program routinely works with a number of partnering entities and organizations across our region to combat invasive weeds. This include local, state, and federal agencies as well local non-profits and watershed councils. Our partnerships also […]
This past season we have seen a rise in the number of Oblong spurge (Euphorbia oblongata) sites appearing in Clackamas County. Oblong spurge is a class A noxious weed in the state of Oregon, and eradication of this species is required across the state. It is known to be highly aggressive and can displace native […]
There are a whole host of terms to describe weeds. The term “weeds” itself can refer to any plant that occurs in an undesirable location. Terms like “non-native“, “exotic“, “alien” or “non-indigenous” refer to plants that occur in areas where they historically did not occur. These terms make no distinction whether plants are desirable or undesirable. The term “invasive” refers to a plant or animal that exhibits aggressive growth and displace other species. Other terms like “noxious” or “nuisance” refer to plants that have special designation by the state or by a municipality the prohibits their sale or cultivation. With this broad diversity of terms, it is no wonder that many people find themselves confused and wondering how to make sense of it all.
At the WeedWise program, we hope to clarify this issue by focusing on plants we refer to as “invasive weeds”. Invasive weeds are plants that live outside their historic geographical range, and whose aggressive growth habit has a detrimental effect on our social, economic, or ecologic resources. The three key components of invasive weeds are that they:
These three characteristics clarify invasive weeds as those plants that pose the greatest threat to our community. By focusing on invasive weeds the WeedWise program is working to maximize its limited resources to realize the greatest benefit to Clackamas County.
All invasive weeds pose a major threat to the residents of Clackamas County, but some of these pests can be more damaging than others. In addition, the costs to control these invasive weeds greatly exceeds the resources available for their management. As a result, the WeedWise program has prioritized its efforts to target invasive weeds that pose the greatest risk, have the greatest negative impact, and may still be limited enough in their distribution to allow for eradication or containment in Clackamas County. For these “priority” invasive weeds, the WeedWise program may have resources available to assistance Clackamas County landowners to control or manage these weeds. For more common invasive weeds, the WeedWise program offers technical information and consultations to improve your efforts and to make your management practices more effective.
Priority: These weeds are the highest priority and are actively being targeted for eradication by the WeedWise Program. Landowners are encouraged to notify the WeedWise program for assistance with these weeds and to actively control them on their property.
Maintenance: These weeds are damaging and widespread. The WeedWise Program encourages control by landowners and can assist with the development of a plan to control these weeds.
| Common Name | Scientific Name | WeedWise Classification | Oregon Classification | Washington Classification | 4-County CWMA | Columbia Gorge CWMA |
|---|---|---|---|---|---|---|
| Velvetleaf | Abutilon theophrasti | B | B | B | B | |
| Barbed Goatgrass | Aegilops triuncialis | priority | A,T | not listed | A | W |
| Tree of Heaven | Ailanthus altissima | maintenance | B | C | B | C |
| Garlic mustard | Alliaria petiolata | priority | B,T | A | B | A |
| False indigo bush | Amorpha fruticosa | B | B | not listed | B | |
| Wild chervil | Anthriscus sylvestris | maintenance | not listed | B | not listed | B |
| Italian arum | Arum italicum | maintenance | not listed | C | B | B |
| False brome | Brachypodium sylvaticum | priority | B | A | B | A |
| Butterfly bush | Buddleja davidii (Buddleja varabilis) | maintenance | B | B | B | B |
| Flowering rush | Butomus umbellatus | priority | A,T | A | W | A |
| Welted thistle | Welted thistle | priority | A,T | not listed | not listed | not listed |
| Drooping sedge | Carex pendula | priority | W | not listed | W | B |
| Meadow knapweed | Centaurea × moncktonii (C. pratensis) | maintenance | B | B | B | B |
| Spotted knapweed | Centaurea stoebe (C. maculosa) | maintenance | B,T | B | B | B |
| Rush skeletonweedr | Chondrilla juncea | priority | B, T | B | D | B |
| Canada thistle | Cirsium arvense | maintenance | B | C | C | C |
| Bull thistle | Cirsium vulgare | maintenance | B | C | D | C |
| Old man's beard | Clematis vitalba | maintenance | B | C | B | C |
| Poison hemlock | Conium maculatum | maintenance | B | B | B | B |
| English hawthorn | Crataegus monogyna | maintenance | not listed | C | C | C |
| Yellow nutsedge | Cyperus esculentus | maintenance | B | B | B | B |
| Houndstongue | Cynoglossum officinale | priority | B | B | D | B |
| Scotch broom | Cytisus scoparius | maintenance | B | B | C | B |
| Wild carrot | Daucus carota | maintenance | not listed | C | C | C |
| Spurge laurel | Daphne laureola | priority | B | B | B | B |
| Common teasel | Dipsacus fullonum | maintenance | not listed | C | C | C |
| South American waterweed | Egeria densa | maintenance | B | B | C | B |
| Myrtle spurge | Euphorbia myrsinites | maintenance | B | B | E | B |
| Oblong spurge | Euphorbia oblongata | priority | A,T | A | A | A |
| Goatsrue | Galega officinalis | priority | A, T | A | A | A |
| Shining geranium | Geranium lucidum | maintenance | B | B | B | A |
| Herb robert | Geranium robertianum | maintenance | B | B | C | B |
| English ivy | Hedera helix | maintenance | B | C | C | B |
| Irish ivy | Hedera hibernica | maintenance | B | C | C | B |
| Giant hogweed | Heracleum mantegazzianum | priority | A, T | A | A | A |
| Orange hawkweed | Hieracium aurantiacum | priority | A,T | B | A | A |
| Meadow hawkweed | Hieracium caespitosum | priority | B,T | B | A | B |
| St. John's wort | Hypericum perforatum | maintenance | B | C | C | C |
| Hairy cat's ear | Hypochaeris radicata | maintenance | not listed | C | C | C |
| Jewelweed | Impatiens capensis | maintenance | W | C | C | W |
| Policeman's helmet | Impatiens glandulifera | priority | B | B | B | B |
| Yellow flag iris | Iris pseudacorus | B | C | B | B | |
| Yellow archangel | Lamium galeobdolon | maintenance | B | B | B | B |
| Large-flowered primrose willow | Ludwigia grandiflora | maintenance | B, T | not listed | not listed | B |
| Primrose willow | Ludwigia hexapetala | maintenance | B, T | B | not listed | B |
| Water primrose | Ludwigia peploides ssp. montevidensis | maintenance | B, T | A | A | A |
| Purple loosestrife | Lythrum salicaria | priority | B | B | B | B |
| Fragrant water lily | Nymphaea odorata | not listed | C | D | C | |
| Small broomrape | Orobanche minor | maintenance | B | not listed | D | A |
| African rue | Peganum harmala | priority | A,T | not listed | A | W |
| Japanese butterbur | Petasites japonica | not listed | not listed | W | B | |
| American pokeweed | Phytolacca americana | W | not listed | B | A | |
| Ribbongrass | Phalaris arundinacea var. picta | maintenance | B,T | C | not listed | C |
| Reed canarygrass | Phalaris arundinacea | maintenance | W | C | not listed | C |
| Bohemian knotweed | Fallopia × bohemica ( Polygonum × bohemicum ) | priority | B | B | C | B |
| Japanese knotweed | Fallopia japonica ( Polygonum cuspidatum ) | priority | B | B | B | B |
| Giant knotweed | Fallopia sachalinensis ( Polygonum sachalinensis ) | priority | B | B | B | B |
| Curly-leaf pondweed | Potamogeton crispus | maintenance | not listed | C | C | C |
| Sulphur cinquefoil | Potentilla recta | priority | B | B | A | B |
| Kudzu | Pueraria montana | priority | A,T | A | A | A |
| Lesser celandine | Ranunculus ficaria | maintenance | B | B | B | B |
| Armenian (Himalayan) blackberry | Rubus armeniacus (R. bifrons, R. procerus, R. discolor) | maintenance | B | C | C | C |
| Evergreen blackberry | Rubus laciniatus | maintenance | not listed | C | C | C |
| Tansy ragwort | Senecio jacobaea | maintenance | B | B | B | B |
| Common groundsel | Senecio vulgaris | maintenance | not listed | C | not listed | C |
| Blessed milk thistle | Silybum marianum | priority | B | A | A | A |
| Perennial sowthistle | Sonchus arvensis ssp. arvensis | maintenance | not listed | C | D | C |
| Common tansy | Tanacetum vulgare | maintenance | not listed | C | C | C |
| Gorse | Ulex europaeus | priority | B,T | B | A | A |
| Garden yellow loosestrife | Lysimachia vulgaris | priority | A,T | B | A | W |
| Spiny cocklebur | Xanthium spinosum | priority | B | C | D | C |
| Syrian bean-caper | Zygophyllum fabago | priority | A | A | A | A |
| Biddy-biddy | Acaena novae-zelandiae | B | not listed | not listed | W | |
| Russian Knapweed | Acroptilon repens | priority | B | B | A | B |
| Pheasant eye | Adonis aestivalis | priority | B | not listed | not listed | not listed |
| Jointed goatgrass | Aegilops cylindrica | priority | B | C | not listed | C |
| Ovate Goatgrass | Aegilops ovata | priority | A | not listed | A | W |
| Camelthorn | Alhagi pseudalhagi | priority | A | B | A | A |
| Blackgrass | Alopecurus myosuroides | not listed | C | A | W | |
| Yellow tuft | Alyssum corsicum | priority | A,T | not listed | A | W |
| Yellow tuft | Alyssum murale | priority | A,T | not listed | A | W |
| Ragweed | Ambrosia artemisiifolia | priority | B | not listed | D | B |
| Skeletonleaf bursage | Ambrosia tomentosa | priority | A | not listed | A | not listed |
| Annual bugloss | Anchusa arvensis | not listed | B | not listed | B | |
| Common bugloss | Anchusa officinalis | priority | B,T | B | A | B |
| Absinth wormwood | Artemisia absinthium | not listed | C | not listed | C | |
| South African capeweed | Artotheca calendula | W | not listed | not listed | W | |
| Giant reed | Arundo donax | priority | W | not listed | not listed | A |
| Common barberry | Berberis vulgaris | not listed | C | not listed | W | |
| Hoary allysum | Bertoa incana | priority | A,T | B | A | B |
| White bryonia | Bryonia alba | priority | A | B | A | A |
| Fanwort | Cabomba caroliniana | not listed | B | not listed | W | |
| Plumeless thistle | Carduus acanthoides | priority | A,T | B | A | A |
| Musk thistle | Carduus nutans | priority | B | B | E | B |
| Italian thistle | Carduus pycnocephalus | priority | B | A | D | A |
| Slender-flowered thistle | Carduus tenuiflorus | priority | B | A | D | A |
| Smooth distaff thistle | Carthamus baeticus | priority | A | not listed | A | W |
| Woolly distaff thistle | Carthamus lanatus | priority | A,T | not listed | A | W |
| Whitestem distaff thistle | Carthamus leucocaulos | W | not listed | not listed | W | |
| Wild safflower | Carthamus oxyacantha | W | not listed | not listed | W | |
| Longspine sandbur | Cenchrus longispinus | not listed | C | not listed | C | |
| Purple starthistle | Centaurea calcitrapa | priority | A,T | A | A | A |
| Diffuse knapweed | Centaurea diffusa | B | B | B | B | |
| Iberian starthistle | Centaurea iberica | priority | A,T | not listed | A | A |
| Brown knapweed | Centaurea jacea | not listed | B | F | B | |
| Big-headed knapweed | Centaurea macrocephala | W | A | not listed | A | |
| Malta starthistle | Centaurea melitensis | not listed | B | not listed | not listed | |
| Black knapweed | Centaurea nigra | not listed | B | not listed | B | |
| Vochin knapweed | Centaurea nigrescens | not listed | A | not listed | A | |
| Yellow starthistle | Centaurea solstitialis | priority | B | B | A | B |
| Feather-headed knapweed | Centaurea trichocephala | W | not listed | not listed | W | |
| Squarrose knapweed | Centaurea virgata | priority | A,T | not listed | not listed | A |
| Oriental clematis | Clematis orientalis | not listed | A | not listed | A | |
| Field bindweed | Convolvulus arvensis | B,T | C | C | C | |
| Jubata grass | Cortaderia jubata | priority | B | C | W | B |
| Pampass grass | Cortaderia selloana | not listed | C | not listed | C | |
| Common crupina | Crupina vulgaris | B | A | not listed | W | |
| Smoothseed alfalfa dodder | Cuscuta approximata | B | C | not listed | C | |
| Bigseed dodder | Cuscuta indecora | B | not listed | not listed | notlisted | |
| Japanese dodder | Cuscuta japonica | priority | A | not listed | A | W |
| Five-angled dodder | Cuscuta pentagona | B | not listed | not listed | notlisted | |
| Purple nutsedge | Cyperus rotundus | priority | A | not listed | A | A |
| Portuguese broom | Cytisus striatus | B,T | not listed | W | W | |
| Cape ivy | Delairea odorata | priority | A | not listed | A | W |
| Cutleaf teasel | Dipsacus laciniatus | priority | B | not listed | not listed | W |
| Tree echium | Echium pininana | W | not listed | not listed | W | |
| Paterson's curse | Echium plantagineum | priority | A,T | not listed | A | W |
| Viper bugloss | Echium vulgare | W | B | not listed | B | |
| Water hyacinth | Eichhornia crassipes | W | not listed | not listed | not listed | |
| Russian olive | Elaeagnus angustifolia | not listed | C | not listed | C | |
| Hairy willow-herb | Epilobium hirsutum | not listed | B | not listed | B | |
| Spanish heath | Erica lusitanica | B | not listed | W | W | |
| Toothed spurge | Euphorbia dentata | W | not listed | not listed | W | |
| Leafy spurge | Euphorbia esula | priority | B, T | B | B | A |
| Common fennel | Foeniculum vulgare | not listed | B | C | B | |
| French broom | Genista monspessulana | B | A | W | A | |
| Reed sweetgrass | Glyceria maxima | not listed | A | not listed | A | |
| Babysbreath | Gypsophila paniculata | not listed | C | not listed | C | |
| Halogeton | Halogeton glomeratus | priority | B | not listed | not listed | W |
| Texas blueweed | Helianthus ciliaris | not listed | A | not listed | A | |
| Spikeweed | Hemizonia pungens | priority | B | C | not listed | C |
| Yellow hawkweed | Hieracium × floribundum | priority | A,T | B | A | A |
| Polar hawkweed | Hieracium atratum | not listed | B | not listed | W | |
| Whiplash hawkweed | Hieracium flagellare | not listed | B | not listed | W | |
| Queen-devil hawkweed | Hieracium glomeratum | not listed | B | not listed | W | |
| Common hawkweed | Hieracium lachenalii | not listed | B | not listed | B | |
| Pale hawkweed | Hieracium lactucella | not listed | B | not listed | W | |
| Smooth hawkweed | Hieracium laevigatum | not listed | B | not listed | W | |
| Spotted hawkweed | Hieracium maculatum | not listed | B | not listed | W | |
| Wall hawkweed | Hieracium murorum | not listed | B | W | W | |
| Mouse-ear hawkweed | Hieracium pilosella | priority | A,T | B | A | A |
| King-devil hawkweed | Hieracium piloselloides | priority | A,T | B | A | A |
| European hawkweed | Hieracium sabaudum | not listed | B | not listed | W | |
| Hydrilla | Hydrilla verticillata | priority | A | A | W | A |
| Common frogbit | Hydrocharis morsus-ranae | priority | A | not listed | A | W |
| Black henbane | Hyoscyamus niger | not listed | C | not listed | C | |
| Small-flowered jewelweed | Impatiens parviflora | priority | not listed | A | A | A |
| Dyers woad | Isatis tinctoria | B | A | not listed | A | |
| Kochia | Kochia scoparia | priority | B | B | not listed | B |
| Perennial peavine | Lathyrus latifolius | maintenance | B | not listed | C | C |
| Lens-podded whitetop | Lepidium chalepensis | priority | B | not listed | A | B |
| Hoary cress | Lepidium draba | priority | B | C | A | B |
| Perennial pepperweed | Lepidium latifolium | priority | B,T | B | A | B |
| Hairy whitetop | Lepidium pubescens | priority | B | C | not listed | C |
| Lepyrodiclis | Lepyrodiclis holosteoides | not listed | C | not listed | W | |
| Oxeye daisy | Leucanthemum vulgare | maintenance | not listed | C | C | C |
| West Indian spongeplant | Limnobium laevigatum | priority | A | not listed | A | W |
| Dalmatian toadflax | Linaria dalmatica | B, T | B | B | B | |
| Yellow toadflax | Linaria vulgaris | maintenance | B | C | B | C |
| Rose campion | Lychnus coronaria | W | not listed | not listed | W | |
| Wand loosestrife | Lythrum virgatum | not listed | B | not listed | W | |
| Scentless mayweed | Matricaria perforata | not listed | C | not listed | C | |
| Wild four o'clock | Mirabilis nyctaginea | not listed | A | not listed | W | |
| Variable-leaf milfoil | Myriophyllum heterophyllum | not listed | A | not listed | A | |
| Eurasian watermilfoil | Myriophyllum spicatum | priority | B | B | C | B |
| Hybrid watermilfoil | Myriophyllum spicatum × M. sibiricum | not listed | C | not listed | not listed | |
| Parrots feather | Myrophyllum aquaticum | maintenance | B | B | B | B |
| Matgrass | Nardus stricta | priority | A,T | not listed | A | W |
| Yellow floating heart | Nymphoides peltata | priority | A, T | B | A | A |
| Scotch thistle | Onopordum acanthium | priority | B | B | A | B |
| Taurian thistle | Onopordum tauricum | priority | A,T | not listed | A | W |
| Mile-a-minute weed | Persicaria perfoliata | W | not listed | not listed | W | |
| Common reed | Phragmites australis ssp. australis | priority | B | B | A | B |
| Hawkweed oxtongue | Picris hieracioides | not listed | B | not listed | B | |
| Himalayan knotweed | Polygonum polystachyum | priority | B | B | not listed | B |
| Austrian fieldcress | Rorippa austriaca | not listed | C | not listed | C | |
| Creeping yellow cress | Rorippa sylvestris | B | not listed | not listed | A | |
| Sweet briar rose | Rosa rubiginosa ( R.eglanteria ) | W | not listed | not listed | W | |
| Ravennagrass | Saccharum ravennae | priority | A | A | A | A |
| Grass-leaved arrowhead | Sagittaria graminea | not listed | B | not listed | W | |
| Delta arrowhead | Sagittaria platyphylla | A | not listed | A | not listed | |
| Mediterranean sage | Salvia aethiopis | B | A | not listed | A | |
| Meadow clary | Salvia pratensis | not listed | A | not listed | W | |
| Clary sage | Salvia sclarea | W | A | not listed | W | |
| Ricefield bulrush | Schoenoplectus mucronatus | W | A | D | A | |
| Cereal rye | Secale cereale | not listed | C | not listed | C | |
| White cockle | Silene latifolia ssp. alba | not listed | C | not listed | C | |
| Silverleaf nightshade | Solanum elaeagnifolium | priority | A | A | A | A |
| Buffalobur | Solanum rostratum | priority | B | C | D | C |
| Sticky nightshade | Solanum sisymbriifolium | W | not listed | not listed | W | |
| Field Burrweed | Soliva sessilis | not listed | C | not listed | W | |
| Johnsongrass | Sorghum halepense | priority | B | A | E | A |
| Smooth cordgrass | Spartina alterniflora | priority | A, T | A | A | W |
| Common cordgrass | Spartina anglica | priority | A,T | A | A | W |
| Dense-flowered cordgrass | Spartina densiflora | priority | A,T | A | A | W |
| Saltmeadow cordgrass | Spartina patens | priority | A,T | A | A | W |
| Spanish broom | Spartium junceum | priority | B | A | F | A |
| Swainsonpea | Sphaerophysa salsula | B | C | not listed | C | |
| Water soldiers | Stratiotes aloides | priority | A | not listed | A | not listed |
| Medusahead rye | Taeniatherum caput-medusae | priority | B | not listed | C | C |
| Saltcedar | Tamarix ramosissima | B,T | B | W | B | |
| Spurge flax | Thymelaea passerina | not listed | B | not listed | W | |
| European water chestnut | Trapa natans | priority | A | not listed | A | A |
| Puncturevine | Tribulus terrestris | priority | B | B | C | B |
| Coltsfoot | Tussilago farfara | priority | A | B | A | A |
| Narrowleaf cattail | Typha angustifolia | not listed | C | not listed | C | |
| Southern cattail | Typha domingensis | not listed | C | not listed | W | |
| Miniature cattail | Typha minima | not listed | C | not listed | W | |
| White cattail | Typha x glauca | not listed | C | not listed | W | |
| North Africa grass | Ventenata dubia ( V. avenacea ) | B | C | not listed | C | |
| Japanese eelgrass | Zostera japonica | W | C | not listed | W |
