Invasive Species List/Terrestrial Plants

This page contains information on terrestrial plant species on the Invasive Species List. For more general information about the event, see Invasive Species.

Air Potato (Dioscorea bulbifera)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; Order-Dioscoreales; Family-Dioscoreaceae; Genus-Dioscorea; Species-D. bulbifera

Autumn Olive (Elaeagnus umbellata)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Rosales; Family-Elaeagnaceae; Genus-Elaeagnus; Species-E. umbellata
 * Introduced in 1830 as an ornamental. In the 1950s it was widely promoted as a great way to provide wildlife habitat and erosion control in environmentally disturbed areas.

Beach Vitex (Vitex rotundifolia)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Lamiales; Family-Lamiaceae; Subfamily-Viticoideae; Genus-Vitex; Species-V. rotundifolia

Brazilian Peppertree (Schinus terebinthifolius)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Sapindales; Family-Anacardiaceae; Genus-Schinus; Species-S. terebinthifolia

Canada Thistle (Cirsium arvense)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Cirsium; Species-C. arvense

Chinese Tallow (Triadica sebifera)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Malpighiales; Family:-Euphorbiaceae; Subfamily-Euphorbioideae; Tribe-Hippomaneae; Subtribe-Hippomaninae; Genus-Triadica; Species-T. sebifera

Cogongrass (Imperata cylindrica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; (Unranked)-Commelinids; Order-Poales; Family-Poaceae; Genus-Imperata; Species-I. cylindrica

Common Buckthorn (Rhamnus cathartica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Rosales; Family-Rhamnaceae; Genus-Rhamnus; Subgenus-Rhamnus; Species-R. cathartica

Common Teasel (Dipsacus fullonum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Dipsacales; Family-Caprifoliaceae; Genus-Dipsacus; Species-D. fullonum

Dalmatian Toadflax (Linaria dalmatica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Lamiales; Family-Plantaginaceae; Genus-Linaria; Species-L. dalmatica

Diffuse Knapweed (Centaurea diffusa)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Centaurea; Species-C. diffusa

Downy Brome (Bromus tectorum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; (Unranked)-Commelinids; Order-Poales; Family-Poaceae; Genus-Bromus; Species-B. tectorum

Fig Buttercup (Ficaria verna)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; Order-Ranunculales; Family-Ranunculaceae; Genus-Ficaria; Species-F. verna

Garlic Mustard (Alliaria petiolata)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Brassicales; Family-Brassicaceae; Genus-Alliaria; Species-A. petiolata

Giant Hogweed (Heracleum mantegazzianum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Apiales; Family-Apiaceae; Genus-Heracleum; Species-H. mantegazzianum

Hairy Whitetop (Lepidium appelianum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Brassicales; Family-Brassicaceae; Genus-Lepidium; Species-L. appelianum

Houndstongue (Cynoglossum officinale)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-(unplaced); Family-Boraginaceae; Genus-Cynoglossum; Species-C. officinale

Japanese Climbing Fern (Lygodium japonicum)

 * Taxonomy: Kingdom-Plantae; Division-Pteridophyta; Class-Polypodiopsida/Pteridopsida (disputed); Order-Schizaeales; Family-Lygodiaceae; Genus-Lygodium; Species-L. japonicum

Japanese Honeysuckle (Lonicera japonica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Dipsacales; Family-Caprifoliaceae; Genus-Lonicera; Species-L. japonica

Japanese Knotweed (Fallopia japonica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Core eudicots; Order-Caryophyllales; Family-Polygonaceae; Genus-Fallopia; Species-F. japonica

Japanese Spiraea (Spiraea japonica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Rosales; Family-Rosaceae; Genus-Spiraea; Species-S. japonica

Japanese Stilt Grass (Microstegium vimineum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; (Unranked)-Commelinids; Order-Poales; Family-Poaceae; Subfamily-Panicoideae; Tribe-Andropogoneae; Genus-Microstegium; Species-M. vimineum

Johnsongrass (Sorghum halepense)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; (Unranked)-Commelinids; Order-Poales; Family-Poaceae; Genus-Sorghum; Species-S. halepense

Kudzu (Pueraria montana var. lobata)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Fabales; Family-Fabaceae; Subfamily-Faboideae; Tribe-Phaseoleae; Genus-Pueraria; Species-P. montana; Variety-P. m. lobata

Leafy Spurge (Euphorbia esula)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Malpighiales; Family-Euphorbiaceae; Genus-Euphorbia;Species-E. esula
 * Habit: perennial herb. Range in height from 6 to 36 in. Have a taproot that can extend up to 15 ft deep and the root system can extend up to 33 ft deep.
 * Appearance:
 * Stems: hairless, blueish-green, and clustered. Are somewhat woody, drying at the end of the season and persisting into the next summer.
 * Leaves: simple, alternate, linear (long and narrow), smooth margins. Are hairless and 1 to 4 inches long. Also occur as heart-shaped bracts that form a cup-like structure near the flowers.
 * Flowers: yellowish-green and arranged in numerous small clusters, subtended by paired, heart-shaped yellow-green bracts. Each flower develops a capsule containing 3 seeds that are 2-2.5 mm in diameter.
 * Habitat: pastures, grasslands, prairies, roadsides, streams, ditches, and waste areas. It grows in full to part sun in a wide range of soil types, from dry to moist. Prefers dry, well-drained soils.
 * Native range: Caucasus region of western Asia.
 * Introduction: The first collection of leafy spurge in the U.S. was in 1827 in Newbury, Massachusetts and was believed to have been introduced by a ballast dump.
 * Reproduction/life cycle:
 * By seed: flowers May-July, though it may occur until frost. Each flower develops a capsule containing 3 seeds. These capsules open explosively when it is hot and capsules are dry, dispersing seed 15-20 feet. A large plant can produce up to 130,000 seeds that remain viable in the soil 7 to 10 years with adequate moisture. Seeds have notably high germination rates (up to 60-80%).
 * Seeds can be transported by water, wildlife, livestock, vehicles and agriculture and construction equipment. Seeds are also dispersed to new sites in mud on boots and impure materials like mulch, forage and feed grains, crop and grass seed, top soil, and gravel.
 * Vegetatively: also can reproduce from crown and adventitious root buds that over-winter under the soil surface. Can spread outwards at several feet per year this way. Pieces of roots on equipment may spread leafy spurge to new sites.
 * Pollination: Leafy spurge is protogynous, and self-fertilization is limited. Because leafy spurge produces sticky pollen, wind pollination of flowers is unlikely. Insects are important to pollination of leafy spurge flowers.
 * Is one of the earliest plants to emerge in the spring and one of the last to enter dormancy in the fall. This early- and late-season growth makes leafy spurge more competitive over native plants.
 * Seedlings have high mortality, but soon become much more competitive with native vegetation (usually by 4 months). Rarely flower the first year. New shoots from roots systems have the advantage of the nutrient reserves of the already-established root systems.
 * Impact:
 * Infestations reduce desirable forage in rangelands (reducing productivity) and crowd out native species. Infestations also limit the ability to move hay, since if it is grown in an infested field it shouldn’t be moved to non-infested areas.
 * Produces milky sap that irritates the mouth and digestive tract of cattle and some wildlife, though it is palatable to goats and sheep. This sap can cause a rash or blistering in humans. It is suspected that leafy spurge also produces allelopathic chemicals.
 * Control:
 * Prevention: clean equipment thoroughly before moving it to an uninfested site. Do not move hay from infested lands.
 * Manual: young, individual seedlings may be hand-pulled before they develop an extensive root system. Gloves should be worn to avoid dermatitis from the sap.
 * Mechanical: mowing and burning is most effective when used several weeks before herbicide application. Other times this is largely ineffective since leafy spurge just resprouts with the aid of an extensive root system.
 * Cultural: maintain native vegetation. If reseeding after control of infestation, choose competitive early-season grasses that can outcompete the spurge before it becomes well-established.
 * Grazing: avoid improper grazing management. When controlling infestations, sheep and goats find leafy spurge palatable. Cattle avoid it, and the sap is a digestive irritant and results in lesions around the eyes and mouth. Seeds may pass through the digestive systems of sheep and goats, so they should be held at the location for long enough for seed to pass through their digestive system.
 * Biological: The U.S. Department of Agriculture has shown success using six natural enemies of leafy spurge imported from Europe. These include a stem and rootboring beetle (Oberea erythrocephala), four root-mining flea beetles (Aphthona spp.) and a shoot-tip gall midge (Spurgia esulae).
 * Chemical: must be treated multiple times each year for several years to be effective. Cost becomes a problem for large infestations. Also may be coordinated with mowing or burning to increase effectiveness of the treatment.
 * Other:
 * The genetic diversity of leafy spurge in North America has led many experts to believe it is a hybrid between two or more Old World spurges. This extreme plasticity results in quick adaptation to local growing conditions and often-inconsistent responses to management.
 * Hybrids: only the tetraploid cypress spurge type is known to hybridize with leafy spurge, resulting in Euphorbia × pseudoesula. This hybrid has been found in several Canadian territories.

Medusahead (Taeniatherum caput-medusae)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Monocots; (Unranked)-Commelinids; Order-Poales; Family-Poaceae; Genus-Taeniatherum; Species-T. caput-medusae

Mile-A-Minute Weed (Persicaria perfoliata)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Core eudicots; Order-Caryophyllales; Family-Polygonaceae; Genus-Persicaria; Species-P. perfoliata

Multiflora Rose (Rosa multiflora)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Rosales; Family-Rosaceae; Genus-Rosa; Species-R. multiflora

Musk Thistle (Carduus nutans)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Carduus; Species-C. nutans

Old World Climbing Fern (Lygodium microphyllum)

 * Taxonomy: Kingdom-Plantae; Division-Pteridophyta; Class-Polypodiopsida / Pteridopsida (disputed); Order-Schizaeales; Family-Lygodiaceae; Genus-Lygodium; Species-L. microphyllum

Princess Tree (Paulownia tomentosa)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Lamiales; Family-Paulowniaceae; Genus-Paulownia; Species-P. tomentosa

Purple Star Thistle (Centaurea calcitrapa)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Centaurea; Species-C. calcitrapa

Russian Knapweed (Rhaponticum repens)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Rhaponticum; Species-R. repens

Russian Olive (Elaeagnus angustifolia)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Rosales; Family-Elaeagnaceae; Genus-Elaeagnus; Species-E. angustifolia

Saltcedar (Tamarix spp.)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Core eudicots; Order-Caryophyllales; Family-Tamaricaceae; Genus-Tamarix

St. Johnswort (Hypericum perforatum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Malpighiales; Family-Hypericaceae; Genus-Hypericum; Species-H. perforatum

Scotch Broom (Cytisus scoparius)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Fabales; Family-Fabaceae; Genus-Cytisus; Species-C. scoparius

Scotch Thistle (Onopordum acanthium)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Subfamily-Carduoideae; Tribe-Cynareae; Genus-Onopordum; Species-O. acanthium

Spotted Knapweed (Centaurea stoebe)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Centaurea; Species-C. stoebe
 * Appearance:
 * Leaves: rosette leaves are up to about 8 inches long, deeply and alternately lobed. Leaves on the stem are alternate, unstalked, and often hairy, giving them a silvery-gray color. They may be slightly lobed, but are usually unlobed and linear, rarely growing over 3 inches.
 * Flowers: occur in groups of around 25-35 ray flowers in a flower head, usually being pink or purple, and rarely white. Flower heads are up to roughly 0.5 inches in height. Bloom June to October. Bracts of flower heads have short hairs and dark tips, giving a spotted appearance.
 * Impacts:
 * Forms dense monocultures, crowding out native species. May infest rangelands, where it replaces more desirable forage.
 * Decreases infiltration of water into the soil, increasing erosion, and in turn increasing stream sedimentation.

Tree-of-Heaven (Ailanthus altissima)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Sapindales; Family-Simaroubaceae; Genus-Ailanthus; Species-A. altissima

Tropical Soda Apple (Solanum viarum)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Solanales; Family-Solanaceae; Genus-Solanum; Species-S. viarum

Whitetop (Lepidium draba)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Rosids; Order-Brassicales; Family-Brassicaceae; Genus-Lepidium; Species-L. draba

Witchweed (Striga asiatica)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Lamiales; Family-Orobanchaceae; Genus-Striga; Species-S. asiatica

Yellow Star Thistle (Centaurea solstitialis)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Asterales; Family-Asteraceae; Tribe-Cynareae; Genus-Centaurea; Species-C. solstitialis

Yellow Toadflax (Linaria vulgaris)

 * Taxonomy: Kingdom-Plantae; (Unranked)-Angiosperms; (Unranked)-Eudicots; (Unranked)-Asterids; Order-Lamiales; Family-Plantaginaceae; Genus-Linaria; Species-L. vulgaris