Invasive Plants Flashcards (pdf)

http://www.paflora.org/Lesser%20Celandine2.pdf 

http://www.nps.gov/plants/alien/fact/mivi1.htm 

Lesser Celandine (Ranunculus ficaria) 

Status: Invasive. 

Native to: Europe and North America. 

Effect: Crowds out native species and competes 

with early spring wildflowers. 

Distinctive features: Grows in shady moist soil. 

Shiny, dark green, heart-shaped leaves. Flowers 

with 7-12 glossy yellow petals bloom in March and 

April. Unlike similar plants, this plant grows from 

tubers (swollen underground stems like tiny 

potatoes) and forms dense carpets. It also 

produces small white tubers among the leaves 

which wash away during hard rains and take root 

elsewhere. 

Japanese Stiltgrass (Microstegium vimineum) 


Native to: Japan, Korea, China, Malaysia and 

India. 

Effects: Because it is well adapted to low light 

conditions, stilt grass often grows on forest 

floors where it spreads to form extensive 

patches, displacing native species that are not 

able to compete with it. 

Distinctive features: Grows to around 12-24 

inches tall and resembles miniature bamboo. 

Leaves are bright green, lance-shaped, 

asymmetrical, 1 to 3 in. long, and have a distinctive 

shiny midrib (midrib is shiny because of a row of 

reflective hairs along its upper surface. Slender 

stalks of tiny flowers are produced in late summer 

into fall.

http://www.invasive.org/images/768x512/1379045.j 

pg 

http://en.wikipedia.org/wiki/File:Berberis_thunbergi 

i_flowers_in_Pennwood_State_Park.jpg 

http://upload.wikimedia.org/wikipedia/commons/e/e 

f/Berberis_thunb_frt.jpg 


Norway Maple (Acer platanoides) 

Native to: Europe. 

Effects: This tree’s extreme shade tolerance, 

allows it to grow beneath existing trees and 

eventually take over the forest. Forest floors in 

invaded areas have fewer native wildflowers as a 

result of the dense shade cast by this species as 

well as because its shallow roots compete with other 

plants. 

Distinctive features: Typical “maple” shaped leaf is 

usually green, but some red cultivars also exist. It 

can be distinguished from native maples by the 

milky sap that’s exuded by the leaf stem when 

picked. Also, in fall, leaves of the green cultivar 

turn yellow, not red. A yard and street tree 

escapee. 

Japanese Barberry (Berberis thunbergii) 


Native to: Asia. 

Effects: Barberry can grow so thick on the floor of 

forests that it shades out native plants. Barberry 

also affects soil properties, particularly pH, which 

can affect the ability of native plants to grow near 

it. Severe infestations of barberry can form nearly 

impenetrable thorny thickets. 

Distinctive features: This deciduous, spiny shrub 

grows about 5 feet tall. Its small oval leaves are 

produced in clusters of 2-6 on a dwarf shoot with a 

spine at its base. Berries ripen to a bright red color 

and stay on the branches all winter, even after 

leaves are dropped. It can be distinguished from 

native American barberry because its flowers don’t 

grow individually, but rather are joined by short 

stems to a larger, unified stem which, in turn, 

attaches them to the branch. A garden escapee.

http://farm4.static.flickr.com/3396/3543809047_f89609f782.jpg 

http://www.nps.gov/plants/ALIEN/fact/img/romu1.jpg 

http://www.nps.gov/plants/ALIEN/fact/phau1.htm 



Multiflora rose (Rosa multiflora) 

Effects: Large plants can produce 500,000 to 1 million 

seeds a year. It grows fast and forms dense thickets 

that outcompete native tree, shrub and herbaceous 

layer species for light, moisture and nutrients. 

Distinctive features: Multiflora rose has distinctive 

compound leaves, which have 5-11 toothed leaflets 

attached to a common leaf stem or “petiole”, and a 

feathery fringe (stipule) at the base of the petiole 

where the leaf stem joins the branch. Other wild roses 

lack the fringed stipule. Multiflora rose has long, arching 

thorny branches which are covered with clusters of 

fragrant showy 5-petaled white to pink flowers in May 

and June. The rose hips, or fruits that form after the 

flowers die, turn red in the fall and are eaten by birds. 

Common Reed (Phragmites australis) 

Status: Both native and invasive strains exist. However, 

the native strain is now very rare. 

Native to: The invasive strain is native to Europe. 

Effects: Grows so densely that no other species can coexist 

with it, and few animals can squeeze between its 

stems. Its leaves have a lot of stomata on them which 

means that it has high transpiration rates, so the 

wetlands where it grows often dry out over time. 

Distinctive features: Common in ditches, along 

roadsides and in wetlands, this grass can grow to over 15 

feet tall and produces distinctive bushy flowers in the 

late summer. The invasive strain can be told from the 

native strain by the green stems (native Phragmites 

stems are dark red) and leaves with a prominent, pale 

colored midrib (midrib of leaves on native strains is very 

inconspicuous) and green bases on underside (base of 

leaf on underside in native strain is dark red).

http://www.illinoiswildflowers.info/grasses/plants/rc_grass.htm 

https://facultystaff.richmond.edu/~jhayden/landscape_plants/late 

_spring_woody_plants/lonicera_japonica_UR_02s.JPG 

Reed Canary Grass (Phalaris arudinacea) 

Status: Both native and invasive strains exist. 

Native to: Invasive strains are native to Europe and 

Asia. 

Effects: This species is particularly damaging to native 

species in wetlands where it grows so densely that it 

crowds out the native plants. It also produces so much 

seed that, once it’s present it’s hard to remove because 

the seed deposit in the soil is so extensive. It can 

always sprout back and recolonize treated sites. 

Distinctive features: Growing 2 to 5 feet tall, this 

grass thrives in disturbed wetland habitats where it 

forms dense colonies of hairless plants. The leaf blades 

of this species are quite broad at the base and they 

have a rough texture on both surfaces. The flowers 

start to be produced in late May and dry to an 

attractive brown color by the end of the summer. 

Japanese honeysuckle (Lonicera japonica) 



Effects: Japanese honeysuckle invades a variety of 

habitats including forest floors, canopies, roadsides, 

wetlands, and disturbed areas. It can girdle shrubs and 

small trees by twining around them, cutting off the flow 

of water through the plant. It also forms dense mats in 

the canopies of trees, shading everything below. 

Distinctive features: Japanese honeysuckle can be 

distinguished from native honeysuckles by its much 

larger and more “showy” flowers and its large size (vines 

of this species can be 80 feet long and get woody with 

age whereas native honeysuckles grow as shrubs or 

short vines). In addition, its flowers form all along its 

branches, whereas native honeysuckles produce flowers 

only at the tips of their stems.

http://alergielaartemisie.files.wordpress.com/2009/09/arte 

misiavulgaris.jpg 

http://www.mdinvasivesp.org/species/terrestrial_plants/graphics/ 

Spotted_Knapweed_1.jpg 


Mugwort (Artemisia vulgaris) 

Native to: Europe, Asia and northern Africa. 

Effects: This plant presents a problem for farmers 

when it grows as a weed in their crops. It is windpollinated 

rather than insect-pollinated, so its pollen 

may cause allergic reaction among hay fever suffers. 

Distinctive features: This common roadside plant is 

usually 1-3 feet tall. Spikes of inconspicuous greenish 

flowers form at the top of its branches. Leaves are 

arranged alternately (rather than opposite) on the stem 

and are green on top and white and fuzzy underneath. 

Lower leaves are strongly lobed, but they get smaller 

and simpler toward the top of the plant. Can be 

distinguished from Common Ragweed, a similar species, 

because the ragweed flowers open pointing downward. 

Mugwort flowers open pointing upward. 

Spotted knapweed (Centaurea maculosa) 



Effects: Spotted Knapweed kills other plants not by 

poisoning them, but by draining them of nutrition. 

Knapweed forms a symbiotic association with a 

particular fungus in the soil. The fungus steals carbon 

away from nearby grasses, reducing their ability to 

compete. Infested lands may consist of nothing but 

acres and acres of knapweed with seemingly lifeless soil 

beneath it. 

Distinctive features: This plant grows a rosette of 

blue gray leaves from which a number of flowering 

stems grow vertically. Small leaves (bracts) with black 

tips, lay flat against the base of the flower head, giving 

the flower base the distinctive "spotted" look that can 

be used to distinguish this plant from similar species. 

http://www.wildflowers-and-weeds.com/weedsinfo/Centaurea_spp.htm

http://www.guenther-blaich.de/de/Ce041478.jpg 

http://www.veststroi.ru/images/posadka/listvennie/celastrus_orbiculatus/ce 

lastrus_orbiculatus.jpg 

http://www.dgsgardening.btinternet.co.uk/creepingthis1.jpg 

Oriental Bittersweet (Celastrus orbiculatus) 



Effects: This vine winds around tree trunks, cutting off 

transport of water and nutrients and so killing them. 

Dense leaves completely cover other vegetation and 

shade, out-compete and kill even large trees. It spreads 

rapidly and over long distances due to birds eating its 

berries and spreading the seeds. 

Distinctive features: This climbing, woody vine can 

grow to lengths of 60 ft. It has light green, elliptical 

leaves and forms small, inconspicuous, flowers in at the 

bases (axils) of its leaves each spring. When ripe, its 

round green fruits split revealing bright red berries 

that stay attached to the vine into the winter. It is 

distinguished from the very similar American 

bittersweet since the native vine forms its flowers and 

fruits at the ends of branches, rather than in the leaf 

axils. 


Canada thistle (Cirsium arvense) 

Native to: Europe (its name is misleading!) 

Effects: Canada thistle crowds out and replaces native 

plants through shading, competition for soil resources 

and possibly by releasing chemicals that are poisonous to 

other plants. It causes huge problems for farmers by 

spreading by underground rhizomes (runners or roots) 

thereby quickly taking over large areas in crop fields. 

Animals are unwilling to graze in areas where it grows. 

Distinctive features: Grows in patches, unlike native 

thistles which tend to be solitary or scattered. It is 

prickly rather than spiny and has many small heads.

http://www.invasive.org/species/subject.cfm?sub=3023 

http://www.missouriplants.com/Pinkopp/Lamium_amplexicaule_ 

page.html 

http://www.sbs.utexas.edu/bio406d/images/pics/lam/lamium_am 

plexicaule.htm 


Burning Bush (Euonymus alatus) 

Native to: Eastern Asia. 

Effects: In woodlands, this species can replace native 

shrubs. It can grow at high densities, out-competing 

native shrubs. When it does this, its roots form a dense 

mat just below the soil surface and its leaves cast such 

a deep shade that no other plants can grow under it. 

Distinctive features: This shrub can grow up to 20 feet 

tall. An easy way to recognize it from other similar 

plants is to look for the four distinctive corky “wings” 

that grow along its twigs, especially when they are 

young. It gets its name from the fact that its leaves 

turn bright red or purple in the fall. It forms red, berry 

like fruits that split late in the season to reveal 4, 

orange, fleshy seeds. A garden and yard escapee. 

Status: Exotic. 

Henbit (Lamium amplexicaule) 

Native to: Europe, western Asia and northern Africa. 

Effects: Plant is tolerant of sun or shade, heat or cold 

so it can grow almost anywhere. It is often very common 

areas that get plowed or tilled regularly, forming large 

“seas” of pink in the spring. It can also grow from small 

pieces of its stem, so chopping the plant (as happens in 

mowing for example) only helps it spread. It also grows 

well from seed. However, its growth in North American 

habitats has few known negative ecological 

consequences. 

Distinctive features: This tiny, low growing plant has 

square stems. Its rounded leaves have “fluted edges” 

and sprout straight from the stem, opposite to one 

another. The tiny purple flowers form in the leaf axils 

and flowering starts very early in the spring.

http://www.missouriplants.com/Pinkopp/Lamium_purpureum_pa 

ge.html 

http://upload.wikimedia.org/wikipedia/commons/2/24/LythrumS 

alicaria.jpg 


Purple dead nettle (Lamium purpureum) 

Native to: Europe and Asia. 

Effects: Common on roadsides, this weed is commonly 

found in farm fields that are not currently in use, as 

well as in waste lands and near human developments. 

Although it doesn’t seem to have strong, negative 

ecological effects, planting or spreading this non-native 

plant should still be avoided. 

Distinctive features: This plant is usually only 4 or 5” 

tall, and has square stems and crowded, overlapping, 

heart-shaped leaves. It also forms tiny “snap-dragon”- 

like purple flowers. The most distinctive characteristic 

of Purple Dead Nettle is the purple tinge of the young 

leaves at the apex of the stem. It is similar to henbit, 

but its leaves have stalks, whereas henbit’s do not. 


Purple loosestrife (Lythrum salicaria) 

Native to: Eurasia. 

Effects: This plant is a very strong competitor in 

natural and disturbed wetlands. It outcompetes and 

replaces native grasses, sedges, and other flowering 

plants that provide a higher quality source of nutrition 

for wildlife. A mature plant can produce 2 -3 million 

seeds per year. 

Distinctive features: This plant can form large clumps 

about five feet tall, with each clump forming numerous 

showy spikes of reddish purple flowers. Each flower has 

five to seven pink-purple petals surrounding a small 

yellow center. Its leaves are long and narrow, and attach 

closely to the four-sided stem opposite to one another 

or in a “whorl”. Purple loosestrife may be distinguished 

from similar looking species by its generally larger size, 

opposite to whorled leaves, and densely packed flowers.

http://luirig.altervista.org/cpm/albums/thome/thome00424-piceaabies.jpg 

http://upload.wikimedia.org/wikipedia/commons/e/e0/Plantago_l 

anceolata_flowers.jpg 



Norway Spruce (Picea abies) 

Effects: Although it spreads relatively slowly, once 

established, Norway spruce forms single-species stands 

because few other plant species can tolerate the newly 

formed habitat. Its dense canopy means it casts a very 

intense shade. In addition, the decomposing needles 

cause the soil to become acidic and make nutrients 

unavailable for uptake by other species. 

Distinctive features: This very large spruce can grow 

more than 150 feet tall. The short (less than 1”) needles 

are square in cross section and dark green on all four 

sides. The needles form a spiral around orange-brown 

branches and are very shade tolerant. Needles of this 

tree can live for many years before being dropped. The 

oval female cones can be as much as 6” long, which is the 

longest of any spruce. Norway spruce is often planted 

as a lawn or border tree. 


English plantain (Plantago lanceolata) 


Effects: This is a common weed on lawns and fields, as 

well as in roadsides and other disturbed habitats. As a 

common lawn weed, it has no known detrimental effects. 

Distinctive features: The slender, 3-ribbed leaves are 

about 3-10” long and form a “rosette” at the soil 

surface. The leaves usually have short hairs. The 

flowers grow from heads that are egg-shaped and are 

about 1” long. The flowers themselves are tiny. The 

open flowers have protruding white structures called 

stamens (male flower parts). A similar lawn weed and 

relative, the Common Plantain, has broader smooth 

bright green leaves and a long narrow seed head. The 

tiny flowers are similar.

http://www.weedmapper.org/pocu6picture.htm 

http://www.cnr.uidaho.edu/rx-grazing/Images_Plants/Cheatgrass- 

Evans.jpg, ; http://www.ppws.vt.edu/scott/weed_id/brote.htm 

Japanese knotweed (Polygonum cuspidatum) 



Effects: Considered one of the world’s 100 worst 

invasive weeds, this plant forms thick, dense colonies 

that completely crowd out native species. During peak 

growing season its branches can grow at a rate of 

several inches per day. It is a particular problem along 

river and stream banks where it grows so densely that it 

can choke water flow, causing flooding. 

Distinctive features: The stems of this plant are hollow 

and strongly jointed, resembling bamboo. The leaves are 

“triangular” with flat bases and pointed tips. In August 

and September the long, creamy sprays of tiny flowers 

emerge from the leaf axils. Japanese knotweed was 

originally introduced into the US as an ornamental 

garden plant and escaped into woods, roadsides, and 

disturbed places. 



Downy chess (Bromus tectorum) 

Effects: It usually thrives in disturbed areas like open 

fields, and roadsides, preventing natives from returning 

to the area. In unshaded areas it crowds out native 

grasses forming vast swaths where it is the only species 

present. It dies early in the season and can present a 

fire hazard where abundant because it becomes so dry. 

Distinctive features: Typically a short grass, it has 

distinctively hairy leaves which turn rusty-red to purple 

at maturity, then fade to a straw color as the plant dies. 

It also recognized from its generally hairy leaves and 

particularly by a dense cluster of hairs that form near 

where the leaf joins the stem. The flowering stems can 

grow to more than a foot tall, though shorter forms are 

common. The seed heads tend to droop slightly and the 

plant has an overall “wispy”, delicate appearance.

http://www.wildstauden.ch/pflanzen/bilder_db/HypochoerisRadi 

cata2008.jpg 

http://www.diccionarioplantasnet.es/images/plantas/m/milenrama 

/achillea_millefolium.jpg 



Cats Ear (Hypochoeris radicata) 

Effects: This plant is a common weed in lawns, pastures, 

roadsides and waste areas, but to date seems to have 

few serious ecological consequences for the ecosystems 

where it grows. 

Distinctive features: This plant forms a rosette of 

“dandelion” like leaves that lie flat against the ground. 

Unlike dandelions, though, its leaves are hairy and have 

irregular to rounded lobes on the leaf margins rather 

than the more deeply cut and angular lobes of the 

dandelion. In addition, instead of single flowers, Cats 

Ear flower stalks bear two to seven bright yellow, 

dandelion-like flowers. Like dandelions, leaves and 

flowers excrete a milky juice when broken. It can be 

easily distinguished from the similar Smooth 

Hawksbeard since its stems are smoothly rounded (they 

have no grooves). 

Yarrow (Achillea millefolium) 

Status: Both native and exotic strains exist. 

Native to: In New Jersey, most of the yarrow found in 

the wild is exotic. 

Effects: Very common in pastures, along road-sides and 

in wastelands. It has no known negative effects. 

Distinctive features: This plant has distinctive, fernlike 

leaves that are grayish green and aromatic. The 

leaves attach to the stem alternately, and are 3-5 

inches long. Flower heads are arranged in large, compact 

clusters at the top of the stem, with each cluster 

consisting of 1 or more flower heads. Each flower head 

has 20-25 grayish white, daisy-like flowers. Yarrow has 

been studied for medicinal uses for years and has over 

102 biologically active compounds in it.

http://www.celtnet.org.uk/images/crow-garlic.gif 

http://jeantosti.com/fleurs4/Allium_vineale1.jpg 

http://kamniski-vrh.net/images/lm/trifolium_pratense.jpg 


Native to: Europe and Asia. 

Wild Garlic (Allium vineale) 

Effects: When livestock eat it, the resulting poultry, 

meat, milk and egg products have a garlic taste. Grains 

harvested from fields in which this plant grows as a 

weed may also be tainted with garlic flavor due to 

inclusion of seeds of this plant in the harvested mix. 

Distinctive features: Growing from underground bulbs, 

wild garlic often grows in clumps of several individual 

plants. Its leaves are slender, hollow, cylindrical and 

have a waxy appearance. Typically its tiny green, white 

or purple flowers produce bulblets (tiny bulbs) rather 

than seed, and these bulbs often sprout leaves while 

still on the flower head. The key features that allow 

recognition of this species are its round, hollow leaves 

and garlic-like odor. The similar and related wild onion 

plant has flat, solid leaves and leaves of other plants 

with similar appearance lack the distinctive garlic odor. 


Red Clover (Trifolium pratense) 

Native to: Europe and Western Asia. 

Effects: Red clover is often planted as a component of 

pasture and forage mixes, but sometimes escapes to 

become a weed of turfgrass, lawns, landscapes, and 

orchards. 

Distinctive features: Leaves consist of 3 oval leaflets 

(trifoliate) usually with a light green or white 'Vshaped' 

marking on each. They are usually hairy on both 

surfaces but sometimes are just hairy on the underside. 

Pink to red flowers form oval clusters at the top of 

stalks an inch or two tall. Trifoliate leaves and pink to 

red flowers are both key features for identifying red 

clover. There are many other clover species, the most 

similar of which is white clover, which has smaller, but 

similar shaped leaves, and much smaller white flowers.

http://www.rbgsyd.nsw.gov.au/__data/assets/image/0007/84544/ 

Trifolium_arvense_plant_620.JPG 

http://zipcodezoo.com/Photos/Polygonum_perfoliatum_5.jpg, 

http://www.hort.uconn.edu/mam/speciesID.html 


Rabbit foot clover (Trifolium arvense) 

Native to: Europe and Western Asia. 

Effects: Thrives on even very dry, sandy, and gravelly 

soils. Its excessive hairiness causes cattle to dislike it. 

When eaten by horses, the fuzzy flower-heads can 

collect into “hair-balls”, closing the intestines and 

occasionally causing a very distressful form of death. 

Distinctive features: Growing to 4 to 16 inches in 

height, this hairy plant has many branches. Leaves 

consist of 3 long, thin leaflets (trifoliate) with short 

hairs at their edges. The dense, fuzzy cylindrical flower 

heads are ½ to 1 inch long, and are made up of tiny 

flowers with feathery “petals”, resulting in a fluffy 

“rabbit’s foot” appearance. Colors range from pale pink 

to whitish gray. Each plant has numerous flower heads 

on many branches. 

Mile a Minute Vine (Polygonum perfoliatum) 



Effects: This plant can grow 6” per day in peak growing 

season, winding around other plants, and blocking light 

from their leaves. The weight of the vine can bend or 

break even relatively thick tree branches. Large 

infestations of mile-a-minute vine eventually reduce 

native plant species in natural areas. 

Distinctive features: This rapidly growing vine can grow 

to more than 20 feet in length. It can be distinguished 

from other similar vines by its distinctly triangular 

leaves that alternate along its long, delicate branches. 

It has small, sharp, curved barbs on its stems and 

saucer-shaped leaves at the nodes between branches. 

Its flowers are small, white and generally inconspicuous 

but the fruits that form at the ends of its branches are 

attractive, deep blue and are arranged in clusters.

http://www.beas-gaertnerei.de/images/Chrysanthemumleucanthemum-M.gif 

http://www.raems.com/edibles/burdock2.jpg 

Ox-eye daisy (Chrysanthemum leucanthemum) 



Effects: Oxeye daisy can form dense colonies that 

decrease abundance of native plants 50%. When it gets 

abundant it can increase potential for soil erosion. 

Distinctive features: Plants initially develop as a 

rosette of leaves near the ground. Rosette leaves have 

rounded teeth or lobes and are widest at the apex and 

taper to the base. Leaves alternate up the flowering 

stem, getting progressively smaller as they go. Flower 

heads are 1-2 inches in diameter and consist of 20 to 30 

white outer petals (ray flowers) that are 10 to 15 mm 

long and many yellow inner flowers (disk flowers) in the 

center. This daisy is easy to identify as no other wild 

plant makes such a large white flower head. In addition, 

the hairless nature of its leaves help set it apart from 

similar species. 



Burdock (Arctium minus) 

Effects: Indirectly affects the development of crops by 

hosting powdery mildew and root rot. Reduces value of 

sheep’s wool when its seed heads get entangled in it. 

Distinctive features: In its first year of growth this 

plant grows as a rosette near the ground. Then, in the 

second year, it sends up a stout, grooved, rough stem 

with multiple branches that grow 2-6 feet tall. The 

large, heart-shaped leaves are dark green and smooth 

above and whitish green underneath. They attach to the 

stem alternately rather than opposite one another. This 

plant produces numerous pink, purple or white flowers 

clustered together in flowering heads that are about ¾ 

inch across. Each head is enclosed in a prickly burr with 

numerous hooked spines on its tips. This plant flowers 

between July and October.

http://www.naturephoto-cz.eu/pic/bilek/daucus-carota-l.-subsp.carota-0192.jpg 

http://www.biopix.dk/Temp/JCS%20Senecio%20vulgaris%2028380.jpg 

http://www.co.whatcom.wa.us/publicworks/pdf/weeds/groundsel2.pdf 



Queen Anne’s Lace (Daucus carota) 

Effects: Because it spreads rapidly by seed and springs 

back after mowing, this biennial plant is considered a 

serious pest in some states. 

Distinctive features: A close relative to the domestic 

carrot, this plant’s leaves look very similar. The first 

year, the leaves form a rosette, then the second year a 

coarsely hairy flowering stem is produced that can grow 

to more than 3 ft. in height. Leaves sprouting from the 

flowering stems are alternate. A flat-topped cluster of 

small, white flowers forms at the top of the stem. The 

presence of a single reddish purple flower in the middle 

of this cluster is distinctive of the species, but is not 

always present. A similar-looking member of this plant 

family, Poison Hemlock, has grooved, purple-spotted 

stems and is hairless. 



Common groundsel (Senecio vulgaris) 

Effects: A common weed in disturbed landscapes, 

nursery crops and occasionally agricultural crops, it is 

poisonous to livestock and may be poisonous to wild 

animals, but generally isn’t believed to have any strong 

impacts on the ecosystems where it grows. 

Distinctive features: When young, it forms a rosette of 

deeply lobed leaves which later produces a hollow 

flowering stem that’s about 6 – 18” tall. At the top of 

these stems, clusters of cigar-shaped flower-heads 

form, with each consisting of many tiny yellow flowers. 

Its seeds are produced in a small dandelion-like puffball. 

It can be told from a similar exotic species, sticky 

groundsel, because the latter has foul-smelling foliage 

that, as its name suggests, feels sticky to the touch.

http://www.mitomori.co.jp/hanazukan/image2/yasou466enoko.jp 

g; http://www.ppws.vt.edu/scott/weed_id/setfa.htm 

http://en.wikipedia.org/wiki/File:Vinca_minor_Nashvillle.jpg 


Nodding Foxtail (Setaria faberi) 


Effects: This plant is a widespread weed that causes 

particular problems when it grows in cornfields, where it 

can, reducing crop yields by more than 10%. 

Distinctive features: Its grass-like leaves are rolled 

when young, and may reach 16 inches long and ¾ inch in 

width when mature. Leaf blades have many short hairs 

on the upper surface and along the margins. The seed 

head is cylindrical, with 1-3 straight bristles emerging 

from each seed, giving the seed head a “furry” 

appearance. The seed head has a characteristic “droop” 

when it is mature. The hairy leaves and drooping seed 

head help distinguish this plant from other similar 

foxtails. 


Periwinkle (Vinca minor) 

Native to: Europe and North Africa. 

Effects: Common periwinkle invades open to shady 

forests, often near homes where it was planted as an 

ornamental. It forms dense and extensive mats along 

forest floors that exclude native vegetation. 

Distinctive features: This plant grows as a vine that 

creeps along the ground, typically not rising more than a 

few inches off the ground. The stems, which are slender 

and green in color, root at the nodes as they creep along 

the ground. The opposite, glossy leaves are 

approximately 1 inch long and elliptical in shape. The 

distinctive bluish-lavender flowers are funnel-shaped 

with five flaring lobes (petals) and about 1” wide. 

Flowering starts in late spring and flowering continues in 

throughout the summer. It can be distinguished from 

the similar, greater periwinkle, which is also invasive, 

because its leaves are smaller and lack hairs on their 

edges.

http://flora.nhm-wien.ac.at/Bilder-A-F/Capsella-bursapastoris.jpg; 

http://www.flickr.com/photos/hedgerowmobile/314197390/ 

http://www.missouriplants.com/Redalt/Polygonum_cespitosum_ 

page.html 

Shepherd’s purse (Capsella bursa-pastoris) 



Effects: Common weed in disturbed areas, roadsides, 

gardens. If dairy cattle or chicken eat a lot of it, this 

plant may affect the flavor of their milk and eggs. 

Distinctive features: The deeply toothed leaves of this 

plant form a rosette about 4-8” in diameter. Smaller, 

slightly toothed, alternate leaves clasp the flower stalk, 

which grows to between 6" and 18" in height. Clusters 

of small white flowers form at the top of this stalk, and 

each flower develops into a heart-shaped stalked seed 

pod. No other plant has this heart-shaped seed pod. 

Cespitose knotweed (Polygonum cespitosum) 



Effects: This plant is mildly toxic so it has few natural 

predators. It is able to thrive in moist habitats, 

dominating the substrate and thus necessary nutrients, 

water, and sunlight to the detriment of native species. 

Distinctive features: This is a slender herbaceous plant 

that can reach sixteen inches in height. Leaves 

alternate along the stem and can reach three inches in 

length and one inch in width. The flowers are reddish 

pink and white and occur between May and September. 

This species can be recognized by presence of a 

characteristic purple splotch in the center of the leaf 

which is present in many but not all specimens.

http://www.floralimages.co.uk/images/ranunculus_bulbosus_93f.jpg 

http://www.freewebs.com/dryadia/Ivy%20(English%20Ivy)%20 

Hedera%20helix.jpg 

http://www.englishivy.net/images/English%20Ivy%202.jpg 

Bulbous buttercup (Ranunculus bulbosus) 



Effects: A common weed of lawns, pastures, and hay 

fields, it can cause blisters in the mouth and intestinal 

tracts of cattle if accidentally eaten. 

Distinctive features: The base of the plant is 

thickened into a structure known as a corm, which 

resembles a bulb, a feature not shared by other similar 

species. Sprouting from the corm are usually several 

grooved, hairy stems, each of which can grow up to 18” 

tall. Its leaves are divided into 3 parts and are sharply 

toothed. This plant is most easily recognized by its 

distinctive, yellow flowers. The 5 petals are so shiny 

that they reflect light. The hairy green sepals that 

surround the flower bend back toward the stem. 



English Ivy (Hedera helix) 

Effects: When climbing trees, this vine can block light 

from the tree’s leaves, eventually killing the tree. The 

additional weight of the vine also makes the trees more 

vulnerable to blowing down in storms. When growing 

along the ground it can often grow so densely that none 

of the native plants are able to coexist with it. 

Distinctive features: This evergreen plant is often 

found climbing trees, brickwork, and other surfaces by 

way of small root-like structures which exude a sticky 

substance. Older vines can reach one foot in diameter 

at their bases. The waxy and somewhat leathery leaves 

are usually three-lobed and dark green with white veins. 

They are arranged alternately along the stem. An 

unlobed, rounded leaf is often found on mature vines. In 

mature plants, pale yellow-green flowers are produced 

at the ends of each branch the fall and these produce 

clusters of black-purple fruits.

http://www.plantsystematics.org/imgs/meredith/r/Elaeagnaceae_Elaeagnus 

_umbellata_26862.html 

http://www.duke.edu/~jspippen/plants/elaeagnus-umbellata060417- 

0706facez.jpg 

http://3.bp.blogspot.com/_3yFTGSOUYSQ/SMfeTHx5cFI/AAA 

AAAAABu0/dgsM7o-8UK4/s400/kudzu-car.jpg 

http://foragesoftexas.tamu.edu/species/images/KUDZU.jpg 


Autumn Olive (Elaeagnus umbellata) 


Effects: This plant grows in a wide variety of habitats, 

and can form such a dense canopy that it shades out all 

of the native species in the area. Birds love to eat its 

berries, and spread its seeds rapidly over long distances. 

Because it can fix nitrogen, Autumn olive changes soil 

chemistry and alters native plant communities. 

Distinctive features: This plant grows as a shrub or 

very small tree (up to 15 feet high). Its smooth-edged 

leaves are oval in shape, approximately 1-3 inches long 

and attach to stems alternately. Upper surface of the 

leaves is dark green to grayish-green in color, while 

lower surface is covered with distinctive silvery white 

scales. Small light yellow flowers give rise to small, 

fleshy pinkish red fruits which are finely dotted with 

pale scales. Autumn olive resembles Russian olive, 

another invasive shrub. Russian olive, however, has a dry 

brownish fruit and its leaves are silvery on both sides. 



Kudzu (Pueraria lobata) 

Effects: Kudzu kills or weakens other plants by 

smothering them under a solid blanket of leaves, by 

girdling woody stems and tree trunks, and by breaking 

branches or uprooting entire trees and shrubs through 

the sheer force of its weight. During peak growing 

season kudzu vines can grow at about one foot per day. 

Distinctive features: Kudzu is a climbing, semi-woody, 

perennial vine that can reach more than 100 feet long. 

Its compound leaves are made up of three broad 

leaflets up to 4 inches across. They branch alternately 

from the vine. Leaflets may be rounded or deeply 2-3 

lobed with hairy margins. Individual flowers, about ½ 

inch long, are purple, highly fragrant and hang from the 

vine in long clusters. The flowers ripen into brown, hairy, 

flattened, seed pods that resemble pea pods.

www.columbia.edu/.../Sturnus_vulgaris1.jpg 

http://www.arkive.org/media/A4/A4D2643D-39EF-4B98- 

8557-09625FAFE339/Presentation.Medium/Female- 

European-starling.jpg 

cdn.wn.com/ph/img/2b/a3/6f763147cc910f18254d6 


Starling (Sturnus vulgaris) 

Native to: Europe, Asia and Northern Africa. 

Effects: Starlings cause problems for agriculture 

because they travel in massive flocks, and a single flock 

of starlings can destroy an entire grain field. They are 

also cavity nesters, and frequently outcompete native 

bird species for nest sites causing decline in abundance 

of these species. 

Distinctive features: European starlings are small 

black birds with an iridescent green and purple gloss on 

their feathers. Feather tips are cream colored, 

creating a characteristic "flecking" effect. In winter, 

the pale tips fade exposing a deep purple gloss on the 

nape, cheeks and throat of breeding males. His back, 

flanks and rump become a deep iridescent green. 

Females lack specialized breeding plumage, are less 

colorful, and have more cream colored flecks. 

House Sparrow (Passer domesticus) 



Effects: Despite their small size, house sparrows are 

quite aggressive. They are known for displacing native 

species by out-competing them for food. In rural areas 

they may also evict native birds from their nests. 

House sparrows eat ripening grains, such as wheat, 

oats, corn, barley and sorghum, and so can be serious 

agricultural pests. 

Distinctive features: The male house sparrow has a 

brown back with black streaks. The top of his head is 

grey, but the sides and back of the neck are chestnut 

red. The chin, throat and upper breast are black and 

the cheeks are white. Females and juveniles are less 

colorful. They have a grey-brown crown and a light 

brown or buff eye stripe. The throat, breast and belly 

are greyish-brown.

http://www.ozanimals.com/image/albums/australia/Bird/Cy 

gnus-olor-portrait-3.jpg 

upload.wikimedia.org/.../4/4f/Cygnus_olor.jpg 

http://www.forestryimages.org/images/768x512/1148052.jpg 

http://www.cals.ncsu.edu/course/ent425/text18/asianlonghornedbeetle.jpg 


Mute Swan (Cygnus olor) 


Effects: Mute swans overgraze aquatic plants, reducing 

food availability to native waterfowl and sometimes 

eliminating their food plants from the ecosystem. They 

are very territorial, often driving native waterfowl 

species from large areas of wetland. Mute swans 

sometimes even attack and injure humans and can be 

especially dangerous to small children. 

Distinctive features: Adult Mute Swans have white 

plumage and orange bills. The head and characteristic 

“S shaped” neck may sometimes be stained brown from 

water and mud containing iron. Legs and feet of adults 

range in color from black to greyish pink. Cygnets (baby 

swans) are greyish brown with grey legs and feet or 

white with pinkish tan feet. 

Long Horn Beetle (Anoplophora glabripennis) 



Effects: This beetle is known to attack and kill at least 

18 species of hardwood trees including maple, birch, 

horse chestnut and elm. 

Distinctive features: The adult Long Horn beetle is 

over an inch in length, and is coal black in color with 

yellow or white spots. It also has distinctively long 

antennae with white bands. The female long horn beetle 

bores holes into the tree’s inner layers to lay her eggs, 

sealing the hole with digested sawdust called “frass”. 

When the eggs hatch, the larvae feed off of the tree’s 

nutrients until they are in the pupal stage. The pupae 

then chew their way out of the tree leaving 

characteristic, circular exit holes.

http://www.acgov.org/cda/awm/agprograms/images/mothsl 

arge.jpg upload.wikimedia.org/.../Lymantria_dispar01.jpg 

http://www.animalpicturesarchive.com/ArchOLD- 

7/1193646010.jpg 

http://farm4.static.flickr.com/3217/2607555614_6fc5cc93f7.jpg 

Status: Invasive 

Gypsy Moth (Lymantria dispar) 

Native to: Europe and Asia 

Effects: Gypsy Moths defoliate the trees they infest. 

This removal of leaves weakens trees, leaving them 

more susceptible to disease. It can even kill trees if 

the same tree is infested repeatedly over several 

years. In the US, Gypsy moths defoliate over 1 million 

acres of forest a year. 

Distinctive features: Male gypsy moths are brown with 

a darker brown pattern on their wings. Females are 

slightly larger and nearly white, with a few dark 

markings on their wings. Newly hatched caterpillars are 

black and hairy, later developing a yellow to gray 

pattern with tufts of bristle-like hairs and subsequent 

rows of blue and red spots on their back. 

Domestic (Rock) Pigeon (Columba livia f. domestica) 

Status: Exotic 

Native to: Europe, North Africa and SW Asia 

Effects: While Rock Pigeons can be a nuisance, they do 

not generally negatively affect native species, since 

they are predominantly found in urban environments. 

Rock pigeons can transmit a number of diseases that 

can affect other birds. Contact with their droppings 

can also pose a minor risk of infection to humans by 

diseases such as toxoplasmosis and salmonella food 

poisoning. 

Distinctive features: The rock pigeon has a dark 

bluish-gray head, neck, and chest with glossy greenish, 

and purple iridescence along its neck and wing feathers. 

Females tend to show less iridescence than males. The 

bill is dark grayish-pink. Most rock pigeons have two 

dark bands across their wings and a bluish-gray band 

across the tail.

http://www.pbase.com/tmurray74/image/63492953 

http://www.forestry.ky.gov/NR/rdonlyres/632A8B73-C700-4F40-840F- 

9ACA71439DAA/0/hemlockwoollyadelgid.jpg 

www.gardensafari.net/pics/kevers/lieveheersbe... 

www.discoverlife.org/IM/I_JP/0159/320/Harmoni 

Hemlock Woolly Adelgid (Adelges tsugae) 


Native to: Japan and China. 

Effects: Nymphs, as well as adults of this species, 

attack and kill hemlock trees by sucking sap from the 

twigs. The trees are weakened and prematurely drop 

their needles. It is estimated that nearly half the 

hemlocks in the Eastern US have been infested by this 

animal, and that the mortality rate of infested trees 

is about 80%. 

Distinctive features: The Hemlock Woolly Adelgid is a 

tiny reddish-purple, aphid-like insect that covers 

itself with a white, waxy secretion. The actually woolly 

adelgids are hard to see. Instead, they are usually 

detected through the presence of the white, cottony 

masses that they build to hide in. These can be found 

on the underside of the needles of infested hemlock 

trees. 

Harlequin Ladybird Beetle (Harmonia axyridis) 



Effects: Harlequin Ladybird Beetles are such 

voracious predators of aphids that they outcompete 

native labdybugs, causing them to starve. When they 

run out of aphids, they eat other insects, including 

native labdybugs, lacewings and butterflies, killing 

them directly. They also are a nuisance to humans, as 

swarms have been known to enter homes, causing 

significant damage. 

Distinctive features: Adult Harlequin Ladybirds are 

larger than other ladybug (5-8mm in length). They are 

oval in shape, but their elytra, (shell covering wings) 

ranges from pale yellow-orange to black bearing, and 

can have anywhere from 0 to 19 spots. The easiest way 

to recognize them is from the “M” shape marking 

behind the head. Larvae are long, flat and spiny, and 

have distinctive black to dark bluish-gray colored 

bodies, with a bright orange patch along their sides.

http://www.ipm.ucdavis.edu/PMG/NE/IMAGES/coccinella_sept 

empunctata.jpg 

http://www.naturephoto-cz.eu/pic/mraz/rattus-norvegicus- 

07B516.jpg 

http://www.biopix.nl/Temp/JCS%20Rattus%20norvegicus%203 

4017.jpg 



Seven spot ladybird beetle 

(Coccinella septempunctata) 

Effects: Like the Harlequin ladybug, this species was 

deliberately introduced to N. America to control 

aphids. It outcompetes and displaces native ladybugs. 

However, it is outcompeted by the Harlequin ladybug 

when both are present. 

Distinctive features: This ladybug can be recognized 

by its red elytra (shell over its wings) and the 

presence of seven spots, 3 on one half of the shell, 3 

on the other and one that’s spread over the junction 

near the head. Larvae are black with yellow spots and 

relatively long legs. 


Norway rat (Ratus norvegicus) 

Native to: Asia (yes, the name is misleading!) 

Effects: This animal is one of the greatest mammal 

pests of all time. More than 150 million of them now 

live within the US and do millions of dollars of damage 

by stealing our food, chewing wires and burrowing 

below buildings and walkways. They can also transmit a 

number of diseases. They can cause trouble for native 

wildlife via stealing eggs and eating young islands, and 

are a particular problem for animals that evolved on 

islands with no natural mammal predators. 

Distinctive features: Norway rats typically have 

coarse, brown fur with a pale gray or grayish brown 

underside. They have small eyes, naked ears, and a 

scaly tail that is shorter than the length of their head 

and body. Mature rats can grow to about 18” long 

(including their tails).

http://www.mus-musculus.com/mouse.jpg 

http://www.taiko.org.nz/cat1.jpg 

http://www.ew.govt.nz/PageFiles/3529/rats2.jpg 


Native to: Central Asia. 

House mouse (Mus musculus) 

Effects: Although not as much of a problem as rats, 

mice too steal food and can cause trouble for people 

as a result of their gnawing and tunneling. They steal 

eggs and eat small animals, but are rarely implicated in 

causing major problems for native wildlife. 

Distinctive features: House mice have light brown to 

dark grayish brown fur with a lighter underside. They 

also have relatively large ears. They grow to about 8” 

long, but more than half of that is tail. Their tail too 

is distinctive in that it has little fur, and has ring like 

grooves along its length. 



Feral cat (Felix cattus) 

Effects: There are more than 70 million feral cats 

roaming the US today. Fierce hunters, each one eats 

several small mammals or birds every day. They also 

eat insects, reptiles, amphibians and even fish. Every 

year billions of native animals are killed and eaten by 

these animals. This adds to the stress of habitat loss, 

and can strongly reduce the ability of native species to 

survive. 

Distinctive features: Although descended from house 

cats, feral cats tend to be smaller and much fiercer. 

After a few generations, feral cats lose the diversity 

of their pampered brethren and to revert to black, 

tabby or tortoiseshell fur patterns, often with some 

white on the belly and breast.

http://freepages.misc.rootsweb.ancestry.com/~larsonmorgan/beetles/beetle%20- 

%20Japanese%20Beetle%20(Popillia%20japonica)%20%5BMO%2006%5D.jpg 

http://www.robsplants.com/images/critters/PopilliaJaponica040802.jpg 

http://sdakotabirds.com/species/photos/house_finch.JPG 

http://www.birdsisaw.com/Photographs/House_Finch_00773.jpg 



Japanese beetle (Popillia japonica) 

Effects: These beetles feed on a wide variety of 

plants including grasses, vegetables, field crops and 

many common garden plants. Because they have no 

natural predators in the US, they can get very 

abundant and do a lot of damage. Every year the US 

spends hundreds of millions of dollars trying to fight 

this animal and its effects. 

Distinctive features: This beetle is oval shaped, with 

a bright metallic green head and thorax. Its elytra 

(wing covers) are brown or reddish-orange. It has 

dense white to grayish hairs underneath, and five 

patches of white hairs along each side of the abdomen, 

as well as two tufts of white hair on its rear. 

House finch (Carpodacus mexicanus) 



Effects: House finches compete with native birds for 

nest cavities, a critical resource already severely 

reduced by loss of natural habitats. House Finches 

also compete for nest boxes installed to benefit native 

birds. 

Distinctive features Adult house finches are 5–6 

inches long with a wingspan of 8–10 inches. Both males 

and females have brown back and wing feathers with 

dark streaks and white tips, and their belly is white 

with brown streaks. The male has red feathers around 

his eye, neck, upper chest, and rump. They look very 

similar to native purple finches. However, purple 

finches are larger, and the bright red coloring is much 

more extensive, covering their entire head, back, 

wings, and chest (which lacks streaks). Female purple 

finches, like female house finches, are drab in color 

but have distinctive white lines above their eyes.

http://img210.imageshack.us/i/lumbricusterrestris2.jpg/ 

http://www.blog.designsquish.com/images/uploads/brooklyn_par 

rots.jpg 


Earth worms (Lumbricus terrestris) 


Effects: New Jersey has no native earthworms. All 

the worms you see today are descendents of worms 

that arrived in soil around plants imported by 

European settlers in the last few centuries. As a 

result, our forests evolved without worms and normal 

forest development depends on the accumulation of 

undecayed leaf matter. When worms decompose that 

leaf layer, the ecology shifts, making the habitat 

unsuitable for certain species of trees, ferns and 

wildflowers. 

Distinctive features: This is a relatively large species 

earthworm. It is pinkish to reddish-brown in color and 

typically reaches 10-25 cm in length. 

Monk parakeet (Myiopsitta monachus) 


Native to: Temperate South America. 

Effects: Can cause damage to field crops and 

orchards. However, biggest problem is caused by its 

large bulky nests which it builds on communication 

towers and power poles. In wet weather nests near 

power lines can short circuit the wires causing power 

outages and requiring costly repairs. 

Distinctive features: This is a small, stocky parrot, 

measuring approximately about 1 foot in total length 

about 1 ¾ feet. It is mostly green with a gray or 

cream face, cheeks, throat and breast and yellow 

underbelly. The flight feathers are blue-black, and the 

tail feathers are long and green. Their strong, parrotlike 

beak is pale orange or dull yellow bill their legs are 

gray legs. They are usually found in loose flocks of 15- 

20 birds, although flocks of up to 100 are not 

uncommon and are very loud birds, making a wide 

variety of screeches, squawks and chattering noises

Invasive Plants Flashcards (pdf)

Create successful ePaper yourself

Delete template?

Save as template?