There is a LOT of information available online about invasive plants and we have barrowed some images and content from various sources in hopes that it will help identify your particular weed problem, or find more information about the plant(s) in question. One of the best resources we found was the U.S. Dept. of Agriculture's NRCS (Natural Resources Conservation Service's 'Plant Database'. You can search their very thorough list of plants and find information about each species, including a distribution map, in their well organized site.
Weed Wrench Works Great on:
Acacia | Burdock | Japanese Barberry | Chinese Elm | Eucalyptus | Tamarisk / Salt Cedar | French Broom | Hackberry | Scotch Broom | Privet | Buckthorn | Multiflora Rose | Honeysuckle | Norway Maple | Gorse | Conifers | Manzanita | Russian Olive | Willow | Holly
AcaciaSource: Wikipedia | Distribution Map
For the same reasons it is favored as an erosion-control plant, with its easy spreading and resilience, some varieties of acacia, namely Acacia mearnsii, are potentially an invasive species. Introduced worldwide it has become an invasive plant which is taking over grasslands and the abandoned agricultural areas, especially in moderate coastal and island regions where mild climate propagates its spreading. Australian/New Zealand Weed Risk Assessment gives it a "high risk, score of 15" rating and it is considered one of the world's 100 most invasive species. Extensive ecological studies should be performed before further introduction of acacia varieties as this fast-growing plant, once introduced, spreads fast and is extremely difficult to eradicate.
BurdockSource: Wikipedia | Distribution Map
Burdock is any of a group of biennial thistles in the genus Arctium, family Asteraceae. Native to the Old World, several species have been widely introduced worldwide.
Plants of the genus Arctium have dark green leaves that can grow up to 28" (71 cm) long. They are generally large, coarse and ovate, with the lower ones being heart-shaped. They are woolly underneath. The leafstalks are generally hollow. Arctium species generally flower from July through to October.
The prickly heads of these plants (burrs) are noted for easily catching on to fur and clothing (being the inspiration for Velcro), thus providing an excellent mechanism for seed dispersal. Burrs cause local irritation and can possibly cause intestinal hairballs in pets. However, most animals avoid ingesting these plants.
The burdocks are sometimes confused with the cockleburs (genus Xanthium) and rhubarb (genus Rheum). Yet, burdock seeds are rounder and softer, and can thus be easily distinguished.
This is a large perenial plant that produces large purple, shaving-brush-like flowers clumped on a large central stalk (up to 6 feet tall). In its first year the basal rosets stay close to the ground. These leaves can be large (up to 2 1/2 feet). During the second spring, a central stalk emerges that bear the flowers.
The purple flowers are surrounded by a large involucral with velcro-like hairs that are used to cling to passing animals and thus aids greatley in its dispersal.
In general the plant is considered a noxious weed not only because of its ability to disperse by attaching itself to mammals and birds, but because of the problems it creates for livestock. The burs can be cause irritation if they cling to the eyes, throught, mouth, or the inside of the stomach. In some cases the seeds must be surgically removed.
Japanese BarberrySource:Wikipedia | Distribution Map
Berberis thunbergii (Japanese barberry or Thunberg's Barberry, also Red Barberry is a species of Berberis, native to Japan and eastern Asia.
It is a dense, deciduous, spiny shrub which grows 1-2 (3) m high. It has deeply grooved, brown, spiny branches with a single (occasionally tridentine) spine (actually a highly modified leaf) at each shoot node. The leaves are green to blue-green, very small, spatula to oval shaped, 12-24 mm long and 3-15 mm broad; they are produced in clusters of 2-6 on a dwarf shoot in the axil of each spine. The flowers are pale yellow, 5-8 mm diameter, produced in drooping 1-1.5 cm long umbrella-shaped clusters of 2â€“5; flowering is from mid spring to early summer. The edible fruit is a glossy bright red to orange-red, ovoid berry 7-10 mm long and 4-7 mm broad, containing a single seed. They mature during late summer and fall and persist through the winter.
In recent years the plant has been recognized as an invasive species in parts of the eastern United States; it is avoided by deer and has been replacing native species. Further, the plant raises the pH of the soil and affects its nitrogen levels. In Canada its cultivation is prohibited as the species can act as a host for Puccinia graminis (black rust), a rust disease of wheat. Currently there are breeding and selection programs aimed at producing cultivars that are either sterile or produce relatively little seed.
Chinese ElmSource: Wikipedia | Distribution Map
A small to medium deciduous, semi-deciduous (rarely semi-evergreen) tree growing to 10â€“18 m (30â€“60 ft) tall with a slender trunk and crown. It has been described as "one of the most splendid elms, having the poise of a graceful Nothofagus". . The leathery, lustrous green single-toothed leaves are small, 2â€“5 cm long by 1â€“3 cm broad, and often retained as late as December or even January in Europe and North America. The apetalous wind-pollinated perfect flowers are produced in early autumn, small and inconspicuous. The fruit is a samara, elliptic to ovate-elliptic, 10â€“13 mm long by 6â€“8 mm broad. The samara is mostly glabrous, the seed at the centre or toward the apex, borne on a stalk 1â€“3 mm in length; it matures rapidly and disperses by late autumn. The trunk has a handsome, flaking bark of mottled greys with tans and reds, giving rise to its other common name, the Lacebark Elm, although scarring from major branch loss can lead to large canker-like wounds.
It is an ornamental tree in urban areas planted for tough durability, interesting bark and yellowish to reddish purple fall foliage as well as being resistant to Dutch elm disease and air pollution. It has escaped intended plantings to invade native plant communities. The aggressive root system absorbs water, nutrient, and space.
It is reported invasive in DC, NC, NE, NJ, VA, and WI
EucalyptusSource: Wikipedia | Distribution Map
Eucalyptus is a diverse genus of flowering trees (and a few shrubs) in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia. There are more than 700 species of Eucalyptus, mostly native to Australia, and a very small number are found in adjacent areas of New Guinea and Indonesia and one as far north as the Philippine archipelago and Taiwan. Only 15 species occur outside Australia, and only 9 do not occur in Australia. Species of Eucalyptus are cultivated throughout the tropics and subtropics including the Americas, Europe, Africa, the Mediterranean Basin, the Middle East, China and the Indian Subcontinent.
Eucalyptus is one of three similar genera that are commonly referred to as "eucalypts," the others being Corymbia and Angophora. Many, but far from all, are known as gum trees because many species exude copious sap from any break in the bark
Eucalyptus has attracted attention from global development researchers and environmentalists. It is a fast-growing source of wood, its oil can be used for cleaning and functions as a natural insecticide, and it is sometimes used to drain swamps and thereby reduce the risk of malaria. Outside their natural ranges, eucalypts are both lauded for their beneficial economic impact on poor populations and derided for being invasive water-suckers, leading to controversy over their total impact.
Eucalyptus forests in California have been criticised because they compete with native plants and do not support native animals. Fire is also a problem. The 1991 Oakland Hills firestorm which destroyed almost 3,000 homes and killed 25 people was partly fueled by large numbers of eucalypts close to the houses.
Eucalyptus trees do exceptionally well in the Pacific Northwest: Washington, Oregon and parts of British Columbia. In some parts of California, eucalypt forests are being removed and native trees and plants restored.
Tamarisk / Salt CedarSource: Wikipedia | Distribution Map
The Tamarix was introduced to the United States as an ornamental shrub, a windbreak, and a shade tree in the early 19th century. In the 1930s, during the Great Depression, tree-planting was used as a tool to fight soil erosion on the Great Plains, and the trees were planted by the millions.
Eight species are found in North America. They can be divided into two sub-groups. The Athel tree (Tamarix aphylla), a large evergreen tree, does not sexually reproduce in the local climate and is not considered a seriously invasive species. The Athel tree is commonly used for windbreaks on the edge of agricultural fields and as a shade tree in the deserts of the Southwestern United States. The second sub-group contains the deciduous tamarisks, which are small shrubby trees, commonly known as "saltcedars." These include Tamarix pentandra, Tamarix tetranda, Tamarix gallica, Tamarix chinensis, Tamarix ramosissima, and Tamarix parvifolia.
These trees establish themselves in disturbed and undisturbed streams, waterways, bottom lands, banks and drainage washes of natural or artificial water bodies, moist rangelands and pastures, and other areas where seedlings can be exposed to extended periods of saturated soil for establishment.
It is commonly believed that Tamarix disrupts the structure and stability of North American native plant communities and degrades native wildlife habitat, by outcompeting and replacing native plant species, salinizing soils, monopolizing limited sources of moisture, and increasing the frequency, intensity and effect of fires and floods.
French Broom / GenistaSource: Wikipedia | Distribution Map
Genista monspessulana (syn. Cytisus monspessulanus or Teline monspessulana) also known as French Broom, Cape Broom and Montpellier Broom, is a woody perennial shrub and a legume. The species is native to the Mediterranean region, and is considered an invasive plant in most places where it has been introduced.
French Broom, Genista monspessulana, grows to 1 to 2.5 m tall, with slender green branches. The leaves are evergreen, trifoliate with three narrow obovate leaflets, 1 to 2 cm long. The flowers are yellow, grouped 3 to 9 together in short racemes. Like other legumes, it develops its seeds within a pod. The pods are 2 to 3 cm long, tough and hard, and are transported easily by flowing water and animals. They burst open with force, dispersing the seeds several metres. The plant begins seed production once it reaches a height of approximately 40 cm, and each plant can live for 10â€“20 years. One mature plant can produce 10,000 seeds per season. The generous seed production and the plant's ability to re-sprout after cutting or burning help it to invade new habitat vigorously when introduced.
When introduced to a new area, French Broom can become an invasive plant. Its reproductive vigour and preference for Mediterranean climates make it a very successful species in California and the Pacific Northwest, where it is considered a severe noxious weed, covering over 40,000 hectares. It is even more widespread in Australia, where it covers 600,000 hectares and is also considered a noxious weed.
The plant often outcompetes native vegetation, forming dense fields where other species are almost completely crowded out. Stands of French broom can be so thick that they make meadows and pastures useless for wild and domestic animals. Other harmful effects include its ability to shade out tree seedlings in reforested areas, its tendency to catch fire, and the toxicity of its leaves and seeds, which contain alkaloids poisonous to many large domestic animals.
HackberrySource: Wikipedia | Distribution Map
Hackberry (Celtis occidentalis), often known as common hackberry, American hackberry or northern hackberry is a genus of about 60-70 species of deciduous trees widespread in warm temperate regions of the Northern Hemisphere, in southern Europe, southern and eastern Asia, and southern and central North America, south to central Africa, and South America. It can grow as large as 80 feet tall by 60 feet wide, according to the Ohio Department of Natural Resources. It commonly invades areas where it establishes itself and then grows quickly.
Scotch BroomSource: Wikipedia | Distribution Map
The Cytisus scoparius plant typically grows from 1 to 3 metres, 3 to 9 feet tall, rarely 4 metres, or 12 feet, with main stems up to 5 cm thick, rarely 10 cm. It is the hardiest species of broom, tolerating temperatures down to about -25&176;C, +10&176;F.
It has been introduced into several other continents outside its native range and is classified as a noxious invasive species in California and the Pacific Northwest in North America, Australia and New Zealand. It commonly grows in disturbed areas along utility and transportation right-of-ways. The prolific growth of this species after timber harvest inhibits reforestation by competing with seedling trees. It is estimated that in Oregon it is responsible for US$47 million in lost timber production each year in that state. Some attempts have been made to develop biological controls in affected areas, using three broom-feeding insects, the psyllid Arytainilla spartiophylla, the beetle Bruchidius villosus, and the moth Leucoptera spartifoliella.
In New Zealand broom is estimated to cost farmers NZ$10 million and the forestry industry NZ$90 million. Biological control for broom has been investigated since the mid 1980s with a number of species being trialled. They include the broom twig miner (Leucoptera spartifoliella), the broom seed beetles (Bruchidius villosus) the broom gall mite (Aceria genistae) the sap-sucking broom psyllid (Arytainilla spartiophila) and recently the broom leaf beetle (Gonioctena olivacea) and the broom shoot moth (Agonopterix assimilella).
PrivetSource: Wikipedia | Distribution Map
Privet was originally the name for the European semi-evergreen shrub Ligustrum vulgare, and later also for the more reliably evergreen Ligustrum ovalifolium (Japanese privet), used extensively for privacy hedging. It is often suggested that the name privet is related to private, but the OED states that there is no evidence to support this. The term is now used for all members of the genus Ligustrum, which includes about 40-50 species of evergreen, semi-evergreen or deciduous shrubs and small trees, native to Europe, north Africa, Asia and Australasia, with the centre of diversity in China, the Himalayas, Japan and Taiwan.
In some parts of the world where they are not native, some privet species have become invasive weeds, spreading into wilderness areas and displacing native species. This is particularly a problem in North America, where no species of the genus occurs naturally. Privet is a huge problem in New Zealand. It is banned from sale or cultivation in New Zealand due to the effects of its pollen on asthma sufferers. Privet pollen is known to cause asthma and eczema in sufferers. Privet can be removed by contacting local government agencies to report its presence
BuckthornSource: Wikipedia | Distribution Map
The Buckthorns (Rhamnus) are a genus (or two genera, if Frangula is treated as distinct) of about 100 species of shrubs or small trees from 1-10 m tall (rarely to 15 m), in the buckthorn family Rhamnaceae. They are native throughout the temperate and subtropical Northern Hemisphere, and also more locally in the subtropical Southern Hemisphere in parts of Africa and South America. Some species are invasive outside their natural ranges.
Both deciduous and evergreen species occur. The leaves are simple, 3-15 cm long, and arranged either alternately or in opposite pairs. One distinctive character of many buckthorns is the way the veination curves upward towards the tip of the leaf. The plant bears fruits which are dark blue berries. The name is due to the woody spine on the end of each twig in many species.
The Purging Buckthorn or Common Buckthorn (R. cathartica) is a widespread European native species, in the past used as a purgative, though its toxicity makes this a very risky herbal medicine and it is no longer used. Introduced into the United States as a garden shrub, this has become an invasive species in many areas there. It has recently been discovered to be a primary host of the soybean aphid Aphis glycines, a problem pest for soybean farmers across the US. The aphids use the buckthorn as a host for the winter and then spread to nearby soybean fields in the spring.
North American species include Alder-leaf Buckthorn (R. alnifolia) right across the continent, Carolina Buckthorn (R. (F.) caroliniana) in the east, Cascara Buckthorn (R. (F.) purshiana) in the west, and the evergreen California Buckthorn or Coffeeberry (R. (F.) californica) and Hollyleaf Buckthorn (R. crocea) in the west.
Buckthorns may be confused with Dogwoods, which share the curved leaf venation; indeed, "dogwood" is a local name for R. prinoides in southern Africa, a plant used to make Ethiopian mead and known as "gesho" in Ethiopia. The two plants are easy to distinguish by slowly pulling a leaf apart; in dogwood thin white latex strings can be seen, strings not present in buckthorn.
Multiflora RoseSource: Wikipedia | Distribution Map
Multiflora rose is a thorny, perennial shrub in the rose family (Rosaceae) growing 10â€“15 feet in height and 9-13 feet in width. Stems are wide arching canes covered with hard thorns. Leaves are alternate, pinnately compound, and have five to eleven sharply toothed oval leaflets. Clusters of showy, fragrant, white to pink flowers begin blooming in May or June. Flowers are 0.5-1 inch wide and have 5 petals. Small bright red fruits, or rose hips, develop during the summer, becoming leathery, and remain on the plant through the winter. It reproduces by seed and by forming new plants that root from the tips of arching canes that contact the ground. Fruits are readily sought after by birds which are the primary dispersers of its seed. It has been estimated that an average plant may produce a million seeds per year, which may remain viable in the soil for up to twenty years.
Rosa multiflora is grown as an ornamental plant, and also used as a rootstock for grafted ornamental rose cultivars. In eastern North America, Multiflora Rose is now generally considered an invasive species, though it was originally introduced from Asia as a soil conservation measure, as a natural hedge to border grazing land, and to attract wildlife. It is readily distinguished from American native roses by its large inflorescences, which bear multiple flowers and hips, often more than a dozen, while the American species bear only one or a few on a branch.
Some places classify Multiflora rose as a "noxious weed". In grazing areas, this rose is generally considered to be a serious pest, though it is considered excellent fodder for goats.
HoneysuckleSource: Wikipedia | Distribution Map
Honeysuckles (Lonicera) are arching shrubs or twining vines in the family Caprifoliaceae, native to the Northern Hemisphere. There are about 180 species of honeysuckle, 100 of which occur in China; Europe and North America have only about 20 native species each. Widely known species include Lonicera periclymenum (European Honeysuckle or Woodbine), Lonicera japonica (Japanese Honeysuckle, White Honeysuckle, or Chinese Honeysuckle) and Lonicera sempervirens (Coral Honeysuckle, Trumpet Honeysuckle, or Woodbine Honeysuckle). Hummingbirds are attracted to these plants.
Japanese honeysuckle (Lonicera japonica) is a high climbing or trailing vine in the family Caprifoliaceae. It was introduced into the United States from Asia. Distribution in the United States is from the central Atlantic states to Missouri and Kansas, south to Florida and Texas. Japanese honeysuckle stems are glabrous to densely pubescent. Leaves are 3/4"-2 1/2" long, evergreen, oval in shape, with a rounded base. In spring the leaves of new shoots are often lobed. The flowers are very fragrant and occur in pairs. They are white or pink when they first appear and fade to yellow with age.
This vine, originally planted as an ornamental and to stabilize road banks, has invaded woodlands, fence rows, and fields, outcompeting and killing native wild flowers, shrubs, and tree seedlings. It is common to abundant at low altitudes, but can spread into uplands. It grows best in full and partial sun but t olerates partial shade. This species is considered a major pest due to its ability to outcompete and shade out native vegetation.
Norway MapleSource: Wikipedia | Distribution Map
Acer platanoides (Norway Maple) is a species of maple native to eastern and central Europe and southwest Asia, from France east to Russia, north to southern Scandinavia and southeast to northern Iran.
It is a deciduous tree growing to 20â€“30 m tall with a trunk up to 1.5 m diameter, and a broad, rounded crown. The bark is grey-brown and shallowly grooved; unlike many other maples, mature trees do not tend to develop a shaggy bark. The shoots are green at first, soon becoming pale brown; the winter buds are shiny red-brown. The leaves are opposite, palmately lobed with five lobes, 7â€“14 cm long and 8â€“20 cm (rarely 25 cm) across; the lobes each bear one to three side teeth, and an otherwise smooth margin. The leaf petiole is 8â€“20 cm long, and secretes a milky juice when broken. The autumn colour is usually yellow, occasionally orange-red. The flowers are in corymbs of 15â€“30 together, yellow to yellow-green with five sepals and five petals 3â€“4 mm long; flowering occurs in early spring before the new leaves emerge. The fruit is a double samara with two winged seeds; the seeds are disc-shaped, strongly flattened, 10â€“15 mm across and 3 mm thick. The wings are 3â€“5 cm long, widely spread, approaching a 180Â° angle. It typically produces a large quantity of viable seeds. It is not particularly a long-lived tree, with a maximum age of around 250 years.
Unfortunately, despite its good looks and urban hardiness, it releases chemicals to discourage undergrowth which tends to create bare, muddy run-off conditions immediately under the tree. A. platanoides has been shown to inhibit the growth of native saplings as a canopy tree or as a sapling. As a result of these characteristics it is considered invasive in some states and has been banned in New Hampshire and Massachusetts. Norway Maple is one of three species that Meijer Garden Centers no longer sell; Meijer made this decision due to the tree's invasive nature. Despite these steps, Norway Maple is still available and widely used for urban plantings in many areas.
GorseSource: Wikipedia | Distribution Map
Gorse, furze, furse or whin (Ulex) is a genus of about 20 plant species of spiny evergreen shrubs in the subfamily Faboideae of the pea family Fabaceae, native to western Europe and northwest Africa, with the majority of species in Iberia.
Gorse is closely related to the brooms, and like them, has green stems and very small leaves and is adapted to dry growing conditions. However it differs in its extreme spininess, with the shoots being modified into branched spines 1â€“4 centimeters (0.39â€“1.6 in) long, which almost wholly replace the leaves as the plant's functioning photosynthetic organs. The leaves of young plants are trifoliate, but are later reduced to scales or small spines. All the species have yellow flowers, some with a very long flowering season.
In many areas of North America, southern South America, Australia, New Zealand and Hawaii, and California the Common Gorse, introduced as an ornamental plant or hedge, has become naturalized and a weed and invasive species due to its aggressive seed dispersal; it has proved very difficult to eradicate and detrimental in native habitats
ManzanitaSource: Wikipedia | Distribution Map
The word manzanita is the Spanish diminutive of manzana (apple). A literal translation would be little apple. The name manzanita is also sometimes used to refer to species in the related genus Arbutus, which is known by that name in the Canadian area of the tree's range, but is more usually known as madroÃ±o, or madrone in the United States
Manzanita is a common name for many species of the genus Arctostaphylos. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from southern British Columbia, Washington to California and New Mexico in the United States, and throughout much of northern and central Mexico. They are characterized by smooth, orange or red bark and stiff, twisting branches. There are 106 species of manzanita, 95 of which are found in the Mediterranean climate and colder montaine regions of California, ranging from ground-hugging coastal and mountain species to small trees up to 20 feet (6m) tall. Manzanitas bloom in the winter to early spring and carry berries in spring and summer. The berries and flowers of most species are edible.
Russian OliveSource: Wikipedia | Distribution Map
Elaeagnus angustifolia (Russian Silverberry, Oleaster, or Russian-olive) is a species of Elaeagnus, native to western and central Asia, from southern Russia and Kazakhstan to Turkey and Iran.
It is a usually thorny shrub or small tree growing to 5 to 7 m in height. Its stems, buds, and leaves have a dense covering of silvery to rusty scales. The leaves are alternate, lanceolate, 4 to 9 cm long and 1 to 2.5 cm broad, with a smooth margin. The highly aromatic flowers are produced in clusters of 1-3 together, 1 cm long with a four-lobed creamy yellow corolla; they appear in early summer and are later replaced by clusters of fruit, a small cherry-like drupe 1 to 1.7 cm long, orange-red covered in silvery scales. The fruit is edible and sweet, though with a dryish mealy texture. Its common name comes from its similarity in appearance to olive (that is trees of the entirely separate family Oleaceae).
WillowSource: Wikipedia | Distribution Map
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere. Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow (from Old English sealh, related to the Latin word salix, willow). Some willows (particularly arctic and alpine species) are low-growing or creeping shrubs; for example the Dwarf Willow (Salix herbacea) rarely exceeds 6 cm (2 in) in height, though spreading widely across the ground.
Willows are very cross-fertile, and numerous hybrids occur, both naturally and in cultivation. A well-known ornamental example is the Weeping Willow (Salix Ã— sepulcralis), which is a hybrid of Peking Willow (Salix babylonica) from China and White Willow (Salix alba) from Europe.
HollySource: Wikipedia | Distribution Map
Holly (Ilex) is a genus of approximately 600 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family.
Holly berries are somewhat toxic to humans, though their poisonous properties are overstated and fatalities almost unknown. They are extremely important food for numerous species of birds, and also are eaten by other wild animals. In the fall and early winter the berries are hard and apparently unpalatable. After being frozen or frosted several times, the berries soften, and become milder in taste. During winter storms, birds often take refuge in hollies, which provide shelter, protection from predators (by the spiny leaves), and food. The flowers are sometimes eaten by the larva of the Double-striped Pug moth (Gymnoscelis rufifasciata). Other Lepidoptera whose larvae feed on holly include Bucculatrix ilecella (which feeds exclusively on hollies) and The Engrailed (Ectropis crepuscularia). Holly is commonly referenced at Christmas time.
Many of the hollies are widely used as ornamental plants in gardens and parks. Several hybrids and numerous cultivars have been developed for garden use, among them the very popular Ilex Ã— altaclerensis (I. aquifolium Ã— I. perado) and Ilex Ã— meserveae (I. aquifolium Ã— I. rugosa). Hollies are often used for hedges; the spiny leaves make them difficult to penetrate, and they take well to pruning and shaping. In Heraldry, holly is used to symbolise truth.