Identification of Virginia’s Noxious WeedsAuthored by Spencer Michael, Graduate Research Assistant, School of Plant and Environmental Sciences, Virginia Tech;Michael Flessner, Associate Professor and Extension Weed Science Specialist, School of Plant and Environmental Sciences,Virginia Tech; and Jacob Barney, Associate Professor, School of Plant and Environmental Sciences, Virginia TechIntroductionIn 2018, giant hogweed was found in Virginia. Gianthogweed is dangerous and harmful to humans ifproper care is not taken for the removal anddestruction of this weed species. Giant hogweed isone of the many examples of how potentiallydangerous noxious weeds can be and why it isimportant to recognize and use proper care whenencountering noxious weeds. The VirginiaDepartment of Agriculture and Consumer Services(VDACS) defines a noxious weed as any livingplant, or part thereof, declared by the Boardthrough regulations under this chapter to bedetrimental to crops, surface waters, includinglakes, or other desirable plants, livestock, land, orother property, or to be injurious to public health,the environment, or the economy, except when instate production of such living plant is commerciallypropagated in Virginia. Weeds deemed noxious aresplit into three tiers by VDACS: Tier 1 beingdefined as “any noxious weed that is not known tobe present in the Commonwealth”, Tier 2 as “anynoxious weed that is present in the Commonwealthand for which successful eradication or suppressionis feasible”, and Tier 3 as “any noxious weed (i) thatis present in the Commonwealth, (ii) whose spreadmay be slowed by restrictions on its movement, and(iii) for which successful eradication or suppressionis not feasible.”This publication provides information onidentification characteristics of Virginia’s noxiousweeds and proper actions that should be taken if aperson believes this weed is growing on theirproperty or if they encounter one of these weeds innature.Tier 1 Noxious WeedsGiant hogweedHeracleum mantegazzianumGiant hogweed was first discovered in Virginia in2018 in the mountain/valley region. There has beenno evidence of giant hogweed spread in the statemeaning that each instance where it has been locatedit was planted there (Flessner and Metzgar 2018).Figure 1. Giant hogweed leaf. (Tina MacIntyre,VDACS)Giant hogweed can be dangerous in certainsituations. If sap contacts the skin in the sunlight, itcan result in severe burning and blistering (Nielsonet al. 2005). Giant hogweed typically grows to be 68 feet tall but can grow to as tall as 18 feet withleaves as wide as 8 feet, stems up to 6 inches across,and flowers clustered up to 1.5 feet across. Leavescan appear similar to cow parsnip (Heracleummaximum), but giant hogweed leaves have acutelobes (figures 1 and 2) (Flessner and Metzgar 2018;Weakley 2015). Giant hogweed can also appearsimilar to poison hemlock (Conium maculatum),wild carrot (Daucus carota), and other species(figures 3 and 4). Consult Virginia CooperativeExtension Publication SPES-48NP for moreinformation: Giant hogweed is also a Federalnoxious weed.
Figure 4. Look-alike species wild carrot. (ShawnAskew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/143)Giant SalviniaSalvinia molestaFigure 2. Giant hogweed in a landscape bed. (MarkSutphin, Virginia Cooperative Extension)Giant Salvinia is an aquatic weed species that floatson the surface of ponds, lakes, and other bodies ofwater (figures 5 and 6). This invasive species is nonnative and is not widespread. It was found anderadicated in Shenandoah County but is present inWashington D.C. (USDA Plants Database). It hashorizontal stems below the water surface and a trioof leaves that form from each node. There are twogreen, oval-shaped leaves above the water surfacewith the third leaf being brown and under the surface(Thayer 2020). Giant Salvinia can form a denseblanket across the water surface, damaging aquaticecosystems by replacing native, desirable plants thatare crucial for the survival of animals and waterfowl(Anonymous a). Giant Salvinia is also a Federalnoxious weed.Figure 3. Look-alike species poison hemlock.(Shawn Askew, Virginia Tech,https://weedid.cals.vt.edu/weedimg/334)Figure 5. Giant Salvinia infestation. (Scott Robinson,Bugwood Images)Virginia Cooperative Extension2
Horsenettle (Solanum carolinense) is a related nativespecies similar in appearance to tropical soda apple,but horsenettle’s leaves, fruits, and size are allsmaller (figure 9). Tropical soda apple is also aFederal noxious weed.Figure 6. Giant Salvinia growing densely on watersurface. (Troy Evans, Bugwood Images)Tropical soda appleSolanum viarumFigure 8. Tropical soda apple in a crop field. (ClydeDowler, Bugwood Images)Tropical soda apple is a perennial shrub that affectsmuch of the southeastern United States. It typicallyimpacts pastures or other areas of forage and isundesirable to animals (Mullahey 2012). Tropicalsoda apple can reach up to 6 feet tall. It is abroadleaf species with leaves that are 6-8 incheslong and 2-6 inches wide. Leaves are similar inappearance to oak leaves and have prickles that formon most of the plant (figures 7 and 8). Flowering canoccur year-round with reproduction typicallyoccurring from September through May. Flowers arewhite, with five petals and a yellow center that formsa point. It produces a fruit that resembles a tinywatermelon (Anonymous 2018a).Figure 9. Look-alike species horsenettle.Shawn Askew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/136)Tier 2 Noxious WeedsBeach vitexVitex rotundifoliaFigure 7. Tropical soda apple. (James Rollins,Bugwood Images)Virginia Cooperative ExtensionBeach vitex is a woody shrub with circular leavestypically found on coastlines. Leaves can be 1-1.5inches long and form in pairs along the stem. Theleaves are smooth and if crushed, produce a spicyfragrance. Plants will flower in early May with mostof the flowers being towards the top of the plant.The flowers will fall off and a green, circular fruit isleft attached to the plant. As winter draws nearer, the3
fruit will dry and turn black (Gresham 2017). It isfound near Virginia Beach, Tidewater, and otherareas with sandy soil.Figure 12. Cogongrass infestation. (Charles T.Bryson, Bugwood Images)Figure 10. Beach vitex foliage. (Randy Westbrooks,Bugwood Images)Figure 11. Beach vitex infestation. (RandyWestbrooks, Bugwood Images)CogongrassImperata cylindricaCogongrass is an invasive species found in much ofthe southern United States. It grows in dense patchesand can become quite tall (up to 6 feet) (figure12).Leaf blades can be up to 6 feet in length and 1 inwide. It has a highly visible line (midrib) off-setfrom the center of the leaf (figure 13). Typically,cogongrass is light green-yellow. After the first frostor freeze, leaves can turn reddish or brown.Seedheads are white or silver and can be from 2-8inches in length and typically blooms from Marchthrough June (Anonymous 2018b).Virginia Cooperative ExtensionIt is found throughout the state of Virginia (USDAPlants Database). Eastern gammagrass (Tripsacumdactyloides), foxtails (Setaria spp.), and othergrasses may appear similar to cogongrass, but do nothave the off-set midrib. Cogongrass is also a Federalnoxious weed.Figure 13. Cogongrass off-center midvein. (ChrisEvans, Bugwood Images)Incised fumewortCorydalis incisaIncised fumewort has been reported in Albemarleand Fairfax counties in Virginia (EDDMapS 2020).It is a biennial that can grow up to 2 feet tall. Thereare large serrations on the leaves and leaves can be1.5-5 inches in length and width (figures 14 and 15).4
whorled. The stem is square-shaped but sometimessix-sided (figure 17). Flowers are purple and can be0.2-0.4 inches in length and have 5-7 petals(Anonymous b) (figure 18). Fireweed (Chamerionangustifolium) looks similar to purple loosestrife buthas a round stem.Figure 14. Incised fumewort leaves and flowers.(Gary Fleming, Bugwood Images)The flower is purple but can also be white. Flowersare approximately 0.5 inches long and petals are notfused. On each flower stalk, there is a green capsulelike fruit that contains seeds. A similar species isyellow fumewort (Corydalis flavula), but it is nativeto the United States and has yellow flowers (Ossi2017).Figure 16. Purple loosestrife growing near water.(Shawn Askew, Virginia Tech,https://weedid.cals.vt.edu/weedimg/535)Figure 17. Purple loosestrife square-shaped stem.(Shawn Askew, Virginia Tech)Figure 15. Incised fumewort infestation.(Daniel rple loosestrifeLythrum salicariaPurple loosestrife is present in most regions ofVirginia except Southside and the Eastern Shore(USDA Plants Database). It is typically found inhigh moisture areas and can be nearly five feet tall(figure 16). Leaves are usually in pairs, butsometimes in groups of three arranged opposite ofeach other along the stem. Leaves sometimes appearVirginia Cooperative ExtensionFigure 18. Purple loosestrife flowers. (Shawn Askew,Virginia Tech)5
Water spinachIpomoea aquaticaWater spinach is an aquatic species typically foundin the southern United States. It is a vine with amilky sap and floats on the surface of water (figure20). Leaves are typically 1-6 inches long with theleaves above the water often being a little longer.Flowers resemble morning glories (Ipomoea spp. L.)and are typically white or pink (figure 19). Itproduces a small fruit that resembles a sphere and istypically around 0.4 inches wide (Richard andRamey 2007). Water spinach is also a Federalnoxious weed.Figure 20. Water spinach infestation. (USDA APHISPPQ, Bugwood Images)Wavyleaf basketgrassOplismenus hirtellusWavyleaf basketgrass has been found in multiplecounties in Virginia including Rockingham, Page,Greene, Madison, Warren, Fauquier, Clarke,Culpeper, Fairfax, Spotsylvania, Albemarle, Nelson,Augusta, Rappahannock, Arlington, Loudon, PrinceWilliam, Stafford, Powhatan, Fredrick andRockbridge (Anonymous 2019). Wavyleafbasketgrass leaves are dark green and are typically1.5-4 inches long and 0.5 inches wide (figure 21).Leaf sheaths are hairy and the plant blooms fromSeptember through November (Westbrooks andImlay, 2009). Seedheads have long, sticky awns thatcling to boots, clothing, animals, and anythingpassing by (figure 22.Figure 19. Water spinach flower and leaf. (FloridaDivision of Plant Industry, Bugwood Images)Figure 21. Wavyleaf basketgrass infestation. (DanielTekiela, Virginia Tech)Wavyleaf basketgrass is similar to another invader,Japanese stiltgrass (Microstegium vimineum), butVirginia Cooperative Extension6
Japanese stiltgrass has silver hairs down themidveins of leaves and comes to a blunt end (figure23). Whereas, wavyleaf basketgrass leaves are wavy,as the name implies, across their width and come toa sharp point. Jointhead arthraxon (Arthraxonhispidus) can also appear similar, but only the leafedges are wavy (figure 24).Figure 22. Wavyleaf basketgrass seeds clinging toskin and clothing. (Daniel Tekiela, Virginia Tech)Figure 24. Look-alike species Jointhead arthraxon(Shawn Askew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/277)Tier 3 Noxious WeedsHydrillaHydrilla verticillataHydrilla is known to occur in Brunswick, Fairfax,Fauquier, Louisa, and Mecklenburg Counties(USDA Plants Database). Hydrilla is a submersedaquatic weed but can reach the surface of water andform a mat (figure 25). Stems are underwater andcan reach up to 25 feet in length. Branching occursnear the surface of water. Leaves are small withpointed tips (figure 26). They are arranged in whorlsof 4-8. Leaf margins are sharp with saw-toothserrations. Leaves are green, but those on the surfacecan be bleached by the sun or be subject to fungusand disease, making them appear yellow orbrownish-green. Hydrilla is dioecious. Femaleflowers are white, solitary, and float on the surface.Male flowers are green and are attached to the stemtips. Male flowers eventually break loose andfertilize the female flower when they come incontact (Ramey and Peichel, 2001). Hydrilla is alsoa Federal noxious weed.Figure 23. Look-alike species Japanese stiltgrass(Shawn Askew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/649)Figure 24. Hydrilla infestation. (ClevelandMetroparks, Bugwood Images)Virginia Cooperative Extension7
Figure 25. Hydrilla growing on water surface. (ChrisEvans, Bugwood Images)Mile-a-minutePersicaria perfoliataMile-a-minute is known to be present in Fairfax,Loudoun, Prince William, Fauquier, Warren,Rappahannock, Culpepper, Madison, Louisa,Carroll, and Grayson Counties and the cities ofRichmond and Suffolk (EDDMapS). Mile-a-minuteweed is common in high moisture areas and the vinecan grow to 20 feet in length. Leaves are uniquelytriangular and are 1-3 inches in length (figure 26).Leaves are light green in the summer months andturn reddish-brown in the winter months (figure 27).Stems have sharp spikes and unique round leaf-likestructures encircle the stem at intervals. Flowers arewhite that are borne on short spikes. Fruits are small,berrylike fruits that are blue. Seeds can be spreadeasily, and it grows extremely quickly (Anonymousc).Figure 26. Mile-a-minute with weevil damage.(Richard Gardner, Bugwood Images)Figure 27. Mile-a-minute weed infestation. (ShawnAskew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/454)VDACS is actively releasing the mile-a-minuteweevil (Rhinoncomimus latipes) that feed on theplant to help control it (figure 26). Mile-a-minutecan resemble two other Persicaria spp.: arrowleaved tearthumb (Persicaria sagittate) andhalberdleaf tearthumb (Persicaria arifolia) butneither has the unique circular leaf-like structuresalong the stem (figures 28 and 29).Figure 28. Look-alike species arrow-leavedtearthumb. (Peter M. Dziuk)Virginia Cooperative Extension8
Figure 29. Look-alike species halberd-leavedtearthumb. (Peter M. Dziuk)Figure 30. Oriental bittersweet leaves and fruits.(Shawn Askew, Virginia al bittersweetCelastrus orbiculatusOriental bittersweet is known to occur along the I-64and I-81 corridors, Northern Virginia, as well asother locations (USDA Plants Database). Orientalbittersweet is a deciduous, climbing, woody vine. Itcan grow up to 60 feet in length and up to 4 inchesin diameter. The bark is often brown to dark brownand the twigs are gray to dark brown. Leaves arealternate and circular in shape (figures 30 and 31).They are typically light green and can be from 2-5inches in length. Flowers are small and greenishwhite. They bloom from May through early June.When fruit is young, they are green and then turnyellow as they mature. When fruits reach maturity,they split and reveal scarlet berries that remain intowinter. It is commonly growing on old homes, fieldsand road edges (Anonymous, 2018d). Orientalbittersweet is commonly mistaken for the nativeAmerican bittersweet (Celastrus scandens). The keyidentification characteristics to distinguish betweenthe two are on oriental bittersweet, the flowers andfruits will grow throughout the length of the stemwhile American bittersweet flowers and fruitsexclusively grow in clusters (USDA 2007).Furthermore, fruits on oriental bittersweet are yellowwhile fruits on American bittersweet are orange andpollen from oriental bittersweet is white whileAmerican is yellow (USDA 2007).Virginia Cooperative ExtensionFigure 31. Oriental bittersweet. (Max Williamson,Bugwood Images)Porcelain berryAmpelopsis brevipedunculataPorcelain berry is known to occur in and aroundRichmond and Northern Virginia as well asAlbemarle and Westmoreland Counties (USDAPlants Database). Porcelain berry is a vine thatclimbs trees (figure 332, similar to kudzu (Puerariamontana var. lobata). Leaves are alternate and haveheart-shaped bases (figure 33). Green/white flowerswill appear from June through August and grape-likefruits will be produced. It will complete maturity9
from August through September. It grows quicklyalong forests, ponds, and streambanks and seeds arespread by water, birds, and other natural occurrences(Anonymous d). Native grapes (Vitis spp.) may looksimilar, but the stem center (pith) is brown in grapeswhile white in porcelain berry.Tree of heavenAilanthus altissimaTree of heaven (figure 34) has been located in nearlyevery county in Virginia (USDA Plants Database). Itis the preferred host for spotted lanternfly, aninvasive insect. It is a rapidly growing dioecioustree, growing as tall as 100 feet and 6 feet indiameter. A young tree will have green bark but as itages will become brown and sometimes gray.Leaves grow from a central stem and can beanywhere from 1-4 feet long and each can contain10-40 leaflets (figure 35). At each leaflets base, thereis a bump and when penetrated will release a vileodor. On female trees, there is a fruit that is 1-2inches long. Each fruit contains one seed and fruitsare in clusters and hang on the tree through winter. Itis a prolific seeder and new shoots can grow fromroots, giving rise to new plants. Tree of heaven canlook like staghorn sumac (Rhus typhina), blackwalnut (Juglans nigra), or hickory (Carya ovata),but each of those have serrations on leaflet edgeswhile tree of heaven does not (Jackson and Grover2018).Figure 32. Porcelain berry infestation. (James H.Miller, Bugwood Images)Figure 34. Tree of heaven in the landscape. (ShawnAskew, Virginia Techhttps://weedid.cals.vt.edu/weedimg/29)Figure 33. Porcelain berry vine with fruits. (JilSwearingen, Bugwood Images)Virginia Cooperative Extension10
Virginia Cooperative Extension Pest ManagementGuides:https://spes.vt.edu/content/ppws vt ent-guides.htmlAcknowledgementsTina MacIntyre with Virginia Department ofAgricultural and Consumer Services.ReferencesFigure 35. Tree of heaven leaf. (Shawn Askew,Virginia Tech)Subsequent ActionsIf you believe you have one of the Tier 1 or 2noxious weeds mentioned above, it is important tocontact your local county extension office(https://ext.vt.edu/offices.html) or VDACS atNoxiousWeed.VDACS@vdacs.virginia.gov toverify identification. Do not transport any viableplant part of the weed without first obtaining apermit from VDACS as this is required by Virginialaw mit.pdf). After identification, your countyextension agent or VDACS representative for Tier 1and 2 weeds will work to form a control plan.Identification and control of noxious weeds iscrucial for preservation of ecosystems and for theoverall well-being of people that have this weed ontheir property.Controlling Tier 3 noxious weeds can be challengingbut worthwhile to protect the local environment.Consult the Additional Resources below to findinformation on controlling these weeds.Additional ResourcesHeffernan, K.E. 1998. Managing Invasive AlienPlants in Natural Areas, Parks, and SmallWoodlands. Natural Heritage Technical Report 9825. Virginia Department of Conservation andRecreation, Division of Natural Heritage. Richmond,Virginia. ent/mnginv.pdfVirginia Cooperative Extension Local Offices:https://ext.vt.edu/offices.htmlVirginia Cooperative ExtensionAnonymous (a). Giant Salvinia. Unites StatesDepartment of ofile/giant-salviniaAnonymous. 2018a. Tropical soda apple. InvasivePlant Atlas of the United html?sub 2446Anonymous. 2018b. Key Identification Features ofCogongrass. Center for Invasive Species andEcosystem Health, University of Anonymous (b). Weed Identification. Virginia TechCollege of Agriculture and Life Sciences.https://weedid.cals.vt.edu/Anonymous (c). Mile-a-minute. Ohio’s NoxiousWeeds. xiousweeds/chapter/mile-a-minute/Anonymous (d). Invasive, Exotic Plants of theSoutheast-Porcelain berry. Going Native, NorthCarolina State University Extensi
Identification of Virginia’s Noxious Weeds . Evans, Bugwood Images) Incised fumewort Corydalis incisa Incised fumewort has been reported in Albemarle It is a biennial that can grow up to 2 feet tall. T
create a noxious weed layer that can go into any government database for their noxious weed inventory. Problems with pesticides To a cattle producer there is no production on land that is covered with noxious weeds. Therefore, he/she has to rent clean it up, he will probably spray Tordon (picloram and 2,4-D) on it, costing him about 100 an acre.
propagate from stem fragments, turions, and subterranean tubers representing a triple threat for management methods. Both plants are listed as noxious weeds on both the Federal Noxious Weed List and the Noxious Weed List for the State of Mississippi. Implementation of monitoring
propagate from stem fragments, turions, and subterranean tubers representing a triple threat for management methods. Both plants are listed as noxious weeds on both the Federal Noxious Weed List and the Noxious Weed List for the State of Mississippi. Both, hydrilla a
Feb 03, 2013 · precedent by exposing a large regulatory gap through which developers may avoid USDA review of GM products.10 In the announcement, APHIS also declined to regulate the bluegrass pursuant to its “noxious weed” authority under the PPA.11 Under the noxious weed program, APHIS can regulate plants that it determines should be listed as noxious weeds.
Office of Indiana State Chemist and Seed Commissioner Noxious weed seeds Prohibited and restricted noxious weed seeds are listed at IC 15-16-7-2 County Weed Boards Noxious weeds Canada thistle, Johnson grass, bur cucumber and shattercane Township Trustees Detrimental plants Canada thistle, Jo
The Coos County Noxious Weed Control District Advisory Board (Advisory Board) provides assistance to control noxious weeds in Coos County. One initiative is to assist landowners through the Cost-Share Program. The County through the Weed Control District will provide up to 40% of the cost of the negotiated price of herbicide and surfactant for .
A coloring book with original drawings and educational information about noxious weeds found in King County, Washington Keywords: coloring, coloring book, noxious weeds, school, weeds, invasive species, king county, washington, Karen Peterson, art, student, kids, children, educational activities Created Date: 3/27/2020 3:23:34 PM
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