Ageratum conyzoides
(billy goat weed)

Pictures

Picture	Title	Caption	Copyright
Title Seedlings Caption A. conyzoides seedlings. Copyright ©Chris Parker/Bristol, UK	Seedlings	A. conyzoides seedlings.	©Chris Parker/Bristol, UK
Title Flowering shoot Caption A. conyzoides is an erect, branching, annual herb with shallow, fibrous roots. The branched, terminal or axillary inflorescence bears 4-18 flower heads arranged in showy, flat-topped clusters. Copyright ©Chris Parker/Bristol, UK	Flowering shoot	A. conyzoides is an erect, branching, annual herb with shallow, fibrous roots. The branched, terminal or axillary inflorescence bears 4-18 flower heads arranged in showy, flat-topped clusters.	©Chris Parker/Bristol, UK
Title Inflorescences Caption A. conyzoides inflorescences. Copyright ©Colin Wilson	Inflorescences	A. conyzoides inflorescences.	©Colin Wilson
Title Leaves Caption Leaves of Ageratum conyzoides (a) and A. houstonianum (b).|Leaves of Ageratum conyzoides (a) and A. houstonianum (b). The leaves of A. conyzoides are opposite, 20-100 mm long, 5-50 mm wide, on hairy petioles 5-75 mm long, broadly ovate, with a rounded or narrowed acute base and an acute or obtuse or sometimes acuminate tip and toothed margins. Copyright ©Chris Parker/Bristol, UK	Leaves	Leaves of Ageratum conyzoides (a) and A. houstonianum (b).|Leaves of Ageratum conyzoides (a) and A. houstonianum (b). The leaves of A. conyzoides are opposite, 20-100 mm long, 5-50 mm wide, on hairy petioles 5-75 mm long, broadly ovate, with a rounded or narrowed acute base and an acute or obtuse or sometimes acuminate tip and toothed margins.	©Chris Parker/Bristol, UK
Title Inflorescences Caption Inflorescences of Ageratum conyzoides (a) and A. houstonianum (b).|Inflorescences of Ageratum conyzoides (a) and A. houstonianum (b). Individual flower heads of A. conyzoides are light blue, white or violet, carried on 50-150 mm long peduncles, and are 5 mm across, 4-6 mm long with 60-75 tubular flowers. The flower head is surrounded by two or three rows of oblong bracts which are green with pale or reddish-violet tops. Copyright ©Chris Parker/Bristol, UK	Inflorescences	Inflorescences of Ageratum conyzoides (a) and A. houstonianum (b).|Inflorescences of Ageratum conyzoides (a) and A. houstonianum (b). Individual flower heads of A. conyzoides are light blue, white or violet, carried on 50-150 mm long peduncles, and are 5 mm across, 4-6 mm long with 60-75 tubular flowers. The flower head is surrounded by two or three rows of oblong bracts which are green with pale or reddish-violet tops.	©Chris Parker/Bristol, UK

Identity

Preferred Scientific Name

• Ageratum conyzoides L.

Preferred Common Name

• billy goat weed

Other Scientific Names

• Ageratum album Willd. Ex Steud.
• Ageratum arsenei B.L.Rob.
• Ageratum ciliare L.
• Ageratum conyzoides var hirtum (Lam.) DC.
• Ageratum cordifolium Roxb.
• Ageratum hirsutum Lam.
• Ageratum hirtum Lam.
• Ageratum humile Salisb.
• Ageratum iltisii R.M.King & H.Rob
• Ageratum latifolium Cav.
• Ageratum microcarpum (Benth.) Hemsl.
• Ageratum muticum Griseb.
• Ageratum nanum Hort. Ex Sch. Bip.
• Ageratum obtusifolium Lam.
• Ageratum odoratum Vilm.
• Ageratum suffruiticosum Regal
• Alomia microcarpa (Benth.) B.L.Rob.
• Cacalia mentrasto Vell.
• Caelestina microcarpa Benth. ex Oerst.
• Caelestina suffruticosa Sweet
• Carelia brachystephana (Regel) Kuntze
• Carelia conyzoides (L.) Kuntze
• Carelia mutica (Griseb.) Kuntze
• Eupatorium conyzoides (L.) E.H.Krause
• Eupatorium paleaceum Sessé & Moc.
• Sparganophorus obtusifolius Lag.

International Common Names

• English: blue flowered groundsel; blue top; goat weed; mother brinkley; tropical ageratum; white weed; winter weed
• Spanish: barba de chivo; catinga de bode; chuva; hierba del perro; hierba del zorro; hierbe de chivo
• French: azier francois; baume blanc; baume mauve; bouton; bouton blan; bouton ble; eupatoire bleue; herbe a femme; herbe a pisser; herbe a sorcier; herbe de bouc; pain doux; petit pain doux; zerisson blanc
• Chinese: hou xiang ji

Local Common Names

• Brazil: agerato; camará apeba; camará iapó; camará japê; camara opela; catinga de barao; catingo do bode; erva de Santa Lucia; erva de Santa Maria; erva de Sao Joao; erva de Sao Jose; macela francesa; maria preta; mentrasto; pica roxo
• Colombia: manrubio
• Cuba: celestina azul; celestina blanca; lora; moratoria
• Dominican Republic: rompezaragüey; yerba de chivo
• East Africa: adwolo; gathenge (Kikuyu); kimavi cha kuku (Kiswahili)
• El Salvador: hierba de perro; mejorana
• Fiji: botekoro; mata mothemothe; mbotembotekoro; sogovanua; sogovanua; songovanua
• French Guiana: azier francois; ponclit; radie francois; raguet-francois
• French Polynesia: maire vaihi; miri
• Gambia: gobu; jambo-serila
• Germany: Leberbalsam, Dürrwurzähnlicher
• Ghana: efoe momoe
• Guam: mumutung
• Guatemala: flor noble; mejoran chaparro; mejorana
• Honduras: cola de alacrán; flor azul; garrapata; hierba de pollo; mozotillo; verbena
• India: gundhaubon; mahakaua; neela phulnu
• Indonesia: babadota; bandotan; berokan; dus-bedusan; wedusan
• Italy: agerato; celestina
• Japan: kakkoazami
• Malaysia: herbe de bouc; rumput pereh jarang; rumput sekedok; ruput tahi-ayam; tahi anjing
• Mauritius: herbe de bouc
• Micronesia, Federated states of: amshiip; olloowaisiip; ololopon; omusiip; opolopon; oponupon; pokaniko; pwisehnkou; uárong nga lípesedj
• Nauru: bwiyat tsige; bwiyat ziege
• Netherlands: ageratum
• Nigeria: imiesu; tamasondji bata
• Niue: sekose sea; tekote tea
• Palau: agmak; ngmak
• Peru: huarmi
• Philippines: asipukpuk; bahu-bahu; bahug-bahug; budbuda; bulak-manok; kakalding; kamabuag; kolokong-kabanyo; kulong-kogong-babae; singilan
• Puerto Rico: mentastro; yerba de cabrío
• Samoa: tae’oti
• South Africa: bokkruid; indringer-ageratum; invading ageratum
• Suriname: bokkeruid; bokki boontje; boko-boko-wiwiri; weti hedem; wetie ete; wit ede
• Taiwan: hwo-hsiang-ji
• Thailand: saapkaa; thiam mae haang; ya-sap-raeng; ya-tabsua
• Tonga: te’ehosi
• Uganda: nnamirembe
• USA: kamabuag; tropic ageratum,
• USA/Hawaii: maile hohono; maile honohono; maile kula
• Vietnam: co cut-heo
• Zambia: kabalakila; kafwaya; nthongola; ntongola
• Zimbabwe: jerimani; nyani

EPPO code

• AGECO (Ageratum conyzoides)

Summary of Invasiveness

A. conyzoides is an annual erect herb reported as an invasive, noxious weed in agricultural lands and as a coloniser of open fields and degraded areas, causing crop yield reductions and affecting biodiversity (Kohli et al., 2006; GISD, 2016; PIER, 2016). It is also a host of pathogens and nematodes that affect crop species (BioNET-EAFRINET, 2016). It is listed as invasive throughout Asia; in Kenya, Mayotte, Morocco, Reunion, Tanzania, South Africa and Uganda in Africa; California (USA) in North America; Cuba in the Caribbean; Easter Island in South America; and in much of Oceania (Oviedo-Prieto et al., 2012; BioNET-EAFRINET, 2016; Encylopedia of Life, 2016; GISD, 2016; PIER, 2016). It is also known to be invasive in Ethiopia, Malawi, Rwanda, and Zambia.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Asterales
•                         Family: Asteraceae
•                             Genus: Ageratum
•                                 Species: Ageratum conyzoides

Notes on Taxonomy and Nomenclature

Ageratum comes from the Greek “a”, not, and “geras”, old age, in reference to the flowers lasting for a long time (Johnson, 1971). Ageratum ranges from Southeastern North America to Central America, but the centre of origin is in Central America and the Caribbean. A. conyzoides is the species designated by Linnaeus as the type for the genus (Johnson, 1971). The epithet conyzoides refers to the species' resemblance to the genus Conyza (Encyclopedia of Life, 2016).

Johnson (1971) recognized two subspecies of A. conyzoides between which there is a genetic barrier to cross fertilization. Although both are natives of South and Central America, the tetraploid (2 n = 40) A. conyzoides (L.) subsp. conyzoides, has been introduced as a weed pantropically. The diploid A. conyzoides (L.) subsp. latifolium (Cav.) M.F. Johnson is restricted to the Americas and some Caribbean Islands. 

The plant has a rank smell, likened in Australia to that of a male goat, hence the common name billy goat weed.

Description

A. conyzoides is an erect, branching, annual herb with shallow, fibrous roots. It may, depending upon environmental conditions, reach 50-1500 mm tall at flowering. The stems, which may root where the bases touch the ground, are cylindrical, and become strong and woody with age; nodes and young parts of the stem are covered with short, white hairs. Leaves are opposite, 20-100 mm long, 5-50 mm wide, on hairy petioles 5-75 mm long, broadly ovate, with a rounded or narrowed acute base and an acute or obtuse or sometimes acuminate tip and toothed margins. Both leaf surfaces are sparsely hairy, rough with prominent veins and when crushed the leaves have a characteristic odour which is reminiscent of the male goat. The branched, terminal or axillary inflorescence bears 4-18 flower heads arranged in showy, flat-topped clusters. Individual flower heads are light blue, white or violet, are carried on 50-150 mm long peduncles and are 5 mm across, 4-6 mm long with 60-75 tubular flowers. The flower head is surrounded by two or three rows of oblong bracts which are green with pale or reddish-violet tops. The bracts are 3-5 mm high, outer ones 0.5-1.75 mm wide, sparsely hairy, evenly toothed in the upper part, with an abruptly acuminate, acute tip. Flowers are 1.5-3 mm long and scarcely protrude above the bracts. The fruit is a ribbed or angled, black achene, 1.25-2 mm long, roughly hairy, with a pappus of 5, rarely 6, rough bristles, white to cream coloured, 1.5-3 mm long with upward turning spines.

Plant Type

Distribution

Native to South and Central America, A. conyzoides is a common pantropical weed that can extend into subtropical and temperate zones where it grows during the summer or as an ornamental (Encyclopedia of Life, 2016; Greuter, 2016). Its native range is not clear, but includes parts of South and Central America and probably the West Indies (Johnson, 1971; Acevedo-Rodríguez and Strong, 2012; PROTA; 2016). It has been recognized as an ornamental and in cultivated crops in Europe since before 1697 (Johnson, 1971). The species is now found in Asia, Africa, North America, Central America, the Caribbean, South America, Europe and Oceania (See Distribution Table for details; Acevedo-Rodríguez and Strong, 2012; PROTA, 2016; PIER, 2016; Missouri Botanical Garden, 2016). Its distribution is perhaps more extensive than currently published because the species is also used as an ornamental. Some records of A. conyzoides, for example in the USA, are probably escapes from cultivation.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

A. conyzoides is regarded as the first Ageratum cultivated in Europe, found in Belgium before 1697 (Johnson, 1971). Other early cultivation records are in England (UK) prior to 1714 and in Sweden by 1748 (Johnson, 1971). In was introduced to the Philippines after being carried on galleons sailing from Mexico to Manila (Johnson, 1971).

Although the species had been recorded before the 1940s in East Africa, it appears to have become more common between 1960 and 1980 (Stadler et al., 1998). This regional spread is correlated with intensification in arable agriculture. Early records were restricted to higher altitudes but with the increasing human population and the associated increase of agricultural activities (e.g. irrigation in arid areas) the weed was able to spread to lower altitudes. The weed has also become dominant on upland maize fields in Vietnam as the length of fallows has declined in recent years with increasing population pressure (Wezel, 2000). The spread had been facilitated by the seeds being readily dispersed on clothing or other items of the traveler and garden escapes having established and formed weedy populations in open cultivated areas.

Introductions

Risk of Introduction

A. conyzoides is a pantropical herb with a high risk of introduction.  It is a common, undesirable weed of agricultural lands along most of its introduced range, and also extensively used as an ornamental (GISD, 2016). It is easily transported as a contaminant in grains, soil, clothes and machinery; all facilitating its unintentional introduction and spread (BioNET-EAFRINET, 2016). Its use as an ornamental also contributes to the species expanding its range.   

Habitat

A. conyzoides grows in grasslands, forests, wastelands, clearings, roadsides, riparian zones, wetlands, coastal dunes, degraded pastures and rapidly colonizes cultivated areas on both light and heavy soils (BioNET-EAFRINET, 2016; PIER, 2016; PROTA, 2016). It occurs as a major to intermediate weed of frequently disturbed areas, such as vegetables and other cultivated crops, pastures (especially when overgrazed), plantations, orchards and roadsides. It can be found in wide-spaced annual row crops and permanent tree crops. It has a facultative wetland and facultative upland wetland indicator status in the USA (USDA-NRCS, 2016); indicating that the species can occur in wetland and non-wetland areas.

Habitat List

Hosts/Species Affected

A. conyzoides is a common weed of plantation crops and overgrazed pastures but can also be found in the important tropical and subtropical annual crops of rainfed or irrigated dryland systems. It has been reported from 36 different crops in 46 countries (Holm et al., 1977).

Host Plants and Other Plants Affected

Biology and Ecology

Genetics

The chromosome number reported for A. conyzoides is 2n=40 (PROTA, 2016). DNA barcode information for the species is available at the Barcode of Life Data Systems (BOLDS, 2016).  

Reproductive Biology

A. conyzoides has no photoperiodic requirement. It is self-incompatible and pollinated by insects, producing up to 40,000 seeds per plant (GISD, 2016; PROTA, 2016). Seeds are dispersed by wind and water (Baker, 1965). A. conyzoides does not possess any marked dormancy (Sauerborn, 1985) but requires light for germination (Sauerborn et al., 1988) and is therefore unable to germinate when buried below the soil surface. Optimum germination has been noted at 20°C but will occur in the range of 15 to 30°C. The lower limit allows it to thrive at higher altitudes. Seed viability is often lost within 12 months (Marks and Nwachuku, 1986).

Physiology and Phenology

A. conyzoides can complete its life cycle in less than 2 months. Although it can flower when less than two true leaves have expanded, it is more commonly seen in favourable conditions as a well-branched plant up to 90 cm tall with hundreds of flower heads (Holm et al., 1977).

Ecology

A. conyzoides  thrives best in rich, moist, mineral soils, and will not grow in the shade (PROTA, 2016). It grows particularly well where soil fertility is high, with dense populations developing when fertilizer is used (Marnotte, 1984). Although preferring a moist habitat, it also grows in dry areas. The drier and less fertile conditions typical of Pacific atolls do not suit the plant so well (PIER, 2004). It is reported at altitudes from sea level to about 2500 m (PROSEA, 2016). 

Climate

Latitude/Altitude Ranges

Air Temperature

Rainfall

Rainfall Regime

Soil Tolerances

Soil drainage

• free
• seasonally waterlogged

Soil reaction

• acid
• alkaline
• neutral

Soil texture

• heavy
• light
• medium

Notes on Natural Enemies

Following a review of natural enemies for A. conyzoides, Waterhouse (1994) provided a long list of insects and pathogens. However, almost all were polyphagous and many were pests of useful plants. Holm et al. (1977) list a number of pathogens and nematodes that have been isolated from A. conyzoides. There is no evidence that these cause significant damage, unlike virus infections, particularly Bidens Mottle Virus (Logan and Zettler, 1984), which can be a problem where A. conyzoides is used for garden bedding. Microcephalothrips abdominalis, which is a vector of the Tobacco Streak Virus, has also been seen affecting A. conyzoides (Sánchez-Monge et al., 2011).

Means of Movement and Dispersal

Natural Dispersal (Non-Biotic)

Seeds are dispersed by wind and water (Baker, 1965).

Vector Transmission (Biotic)

A.  conyzoides seeds are dispersed on the hairs of animals, and attached to clothes and agricultural machinery (BioNET-EAFRINET, 2016).

Accidental Introduction

The species has been reported as a contaminant of garden waste and crops (BioNET-EAFRINET, 2016; PROTA, 2016). It is also accidentally dispersed on clothes and agricultural machinery (BioNET-EAFRINET, 2016). In Yunnan, China, density in correlated with distance from roads, suggesting that primary colonization in this area occurs along road margins (GISD, 2016).

Intentional Introduction

A. conyzoides has been reported as introduced as an ornamental plant in some of its range (Johnson, 1971; BioNET-EAFRINET, 2016) 

Pathway Causes

Pathway Vectors

Plant Trade

Wood Packaging

Impact Summary

Economic Impact

Holm et al. (1977) consider A. conyzoides and A. houstonianum to be among the commonest weeds in warmer regions of the world. A. conyzoides can be expected to be found as an important weed in all crops in the tropics and subtropics, except in deep shade. It is also a weed of turf in Guangxi Province, China (Ma YueFeng et al., 2002). Year-round flowering (providing soil moisture is adequate) and the production of large quantities of seed allows A. conyzoides to heavily infest crops, often carpeting the soil where conditions are favourable.

In East Africa, Holm et al. (1977) report that A. conyzoides is widespread in arable crops from the coast up to 3125 m. They further list it as an important weed of maize in Ghana, Nigeria, the Philippines and Sri Lanka; groundnut in Ghana, Indonesia and Sri Lanka; chillies and upland rice in Indonesia, the Philippines and Sri Lanka; cotton in Uganda; tea in Taiwan, India, Indonesia, Mauritius and Sri Lanka; cocoa in Brazil; potatoes in Colombia; oil palm in Nigeria; and over-grazed pasture in Australia, Hawaii and India. A. conyzoides competes with crops as one component of a mixed weed flora.

Roder et al. (1998) demonstrated that upland rice yield is negatively correlated with A. conyzoides density. In agricultural fields of India where A. conyzoides is found as a weed, there is evidence of yield reduction (Kohli et al., 2006). Wesel (2000) also report a reduced crop yield and a high labour input needed for weed management due to A. conyzoides and other weeds in maize fields in Vietnam. Most of the crop yield reduction is reported as due to germination or growth inhibition by allelopathic compouds produced by A. conyzoides and/or by light competition (GISD, 2016). The species is also a seed contaminant in harvested crops (PROTA, 2016).

A. conyzoides is also important as an alternate host of a number of economically important crop pathogens and nematodes, and where fallowing is practised, can provide a source of infection. It is a symptomless carrier of Burkholderia solanacearum [Ralsonia solanacearum], important in potato in India (Sunaina et al., 1989) and is a host of the banana nematodes Radopholus similis and Helicotylenchus multicinctus in Brazil (Zem and Lordello, 1983) and of the root knot nematode, Meloidogyne javanica, in many parts of the world (e.g. Mamaril and Alberto, 1989). It is also the host of the Tomato Yellow Leaf Curl Tanzania Virus (TYLCTZV) and the Ageratum Yellow Vein Virus (GISD, 2016).

Environmental Impact

Impact on Habitats

A. conyzoides can form monocultures in grasslands, forest, and plantations and fields (Dogra et al., 2009). It is an aggressive short-term colonizer of gaps in vegetation. It can become dominant following overgrazing, a situation reported from Mudumalai Wildlife Sanctuary, Jaldapara Wildlife Sanctuary and Gorumara National Parks in India (Bhowmik et al., 1999; Silori and Mishra, 2001). A. conyzoides can initially dominate as a pioneer where fields are abandoned at shifting cultivation sites in tropical regions.  However, it is rapidly succeeded by pioneer shrub or tree species within a few years (Ohtsuka, 1998). The species is also reported by Dogra et al. (2009) as altering the soil properties by releasing allelochemicals that could inhibit the growth of other species. They also compared the soil composition of areas with native vegetation vs. ones invaded with A. conyzoides, finding a significant increase in organic carbon and other nutrients. They concluded that the increase in soil nutrients and the allelopathic effect promotes the growth of the invasive species.

Impact on Biodiversity

A. conyzoides is one of a number of competitive introduced species which threaten the survival of indigenous species in Hawaii, including Brighamia insignis (Centre for Plant Conservation, 2004). As an alien invader, A. conyzoides is noted to be of special interest in the Kruger National Park in South Africa (National Park Service, 2004). In India, it outcompetes the native grasses in rangelands, causing a shortage of fodder species (Kohli et al., 2006). In the northwestern Himalayas of India, species diversity of areas invaded by A. conyzoides has been drastically affected, with reductions in the number of plant species by 32%, the Margalef’s index of species by 37%, α diversity by 41%, and the evenness index by 15% (Dogra et al., 2009).

Threatened Species

Social Impact

Although A. conyzoides is used as a medicinal plant, it is also reported as toxic, capable of producing liver lesions and tumors (GISD, 2016). PROTA (2016) list it as poisonous to vertebrates but without further details. A. conyzoides has been reported as the main reason of a mass poisoning incident in Ethiopia due to grain being contaminated with the species (Encyclopedia of Life, 2016). It can also cause allergic reactions (GISD, 2016).

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Highly mobile locally
• Fast growing
• Has high reproductive potential
• Has propagules that can remain viable for more than one year

• Increases vulnerability to invasions
• Loss of medicinal resources
• Modification of nutrient regime
• Modification of successional patterns
• Monoculture formation
• Negatively impacts agriculture
• Negatively impacts human health
• Negatively impacts animal health
• Negatively impacts livelihoods
• Reduced native biodiversity
• Threat to/ loss of native species
• Negatively impacts trade/international relations

• Allelopathic
• Causes allergic responses
• Competition - monopolizing resources
• Competition - shading
• Pest and disease transmission
• Poisoning
• Rapid growth

• Highly likely to be transported internationally accidentally
• Highly likely to be transported internationally deliberately
• Difficult to identify/detect as a commodity contaminant

Uses

Social Benefit

Apart from use as a garden ornamental, A. conyzoides plays a role in folk medicine over much of its range, being used to treat a diversity of ailments including skin complaints, cuts, wounds, burns pneumonia, sleeping sickness, stomach ache, malaria, coughs, colds, diarrhoea, as a purgative enema, a painkiller during childbirth and to treat snakebites (Johnson, 1971; PROTA, 2016). It has been reported as having anti-inflammatory and anti-allergic properties, as well as being attributed magical and superstitious properties by some cultures (PROTA, 2016). Its essential oils are used for treating dandruff and as a hair wash (PROTA, 2016). Although cited as poisonous, it is also used as a fodder for cattle, guinea-pigs, horses and goats (PROTA, 2016).

Environmental Services

Maintaining a ground cover of A. conyzoides in citrus orchards is a valuable component of Integrated Pest Management (IPM) of citrus mite as the weed provides refuge for predators of the mites (Zhou et al., 1994). It is also planted as a ground cover in rubber plantations (PROTA, 2016). There is considerable interest in the insecticidal and fungicidal properties of extracts from A. conyzoides, which have shown potential for controlling Dysdercus flavidus, which transmits diseases in cotton in Mauritius, the potato tuber moth (Phthorimaea operculella) and the rice disease (Cochliobolus miyabeanus) (Fagoonee and Umrit, 1980; Asthana et al., 1982; Pandey et al., 1982). Bouda et al. (2001) found that essential oils of A. conyzoides were effective as an insecticide for the control of Sitophilus zeamais, the maize grain weevil. It is attacked easily by the nematode Heterodera radicola [Meloidogyne arenaria], and because of that A. conyzoides is suggested to be planted near other susceptible plants (PROTA, 2016).

Uses List

General

• Ornamental
• Ritual uses

Human food and beverage

• Vegetable

Materials

• Essential oils
• Pesticide
• Poisonous to mammals

Medicinal, pharmaceutical

• Traditional/folklore

Similarities to Other Species/Conditions

The closely related species Ageratum houstonianum is often confused in the herbarium or field with A. conyzoides. The habits, fruit and the strong smell of freshly crushed foliage of both species are similar. However, the combination of ovate leaves with cordate bases and narrowly lanceolate, conspicuously pilose involucre bracts with glandular hairs on the gradually acuminate apex distinguishes A. houstonianum. This species also has larger flower heads of 75-100 flowers compared with 60-75 in A. conyzoides. In the former species the styles are clearly visible extending above the line of the involucral bracts, whereas the flowers of A. conyzoides scarcely extend above the involucre. 

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Prevention

The species is included in the list of noxious weeds for South Africa, acknowledging it as a prohibited plant that needs to be controlled (BioNet-EAFRINET, 2016).

Control

Cultural control

Short periods of flooding provide effective control in Eucalyptus plantations in India (Paradkar et al., 1998). In field crops in the dry tropics, the density of the weed is reduced by minimum tillage systems (Zelaya et al., 1997).

Mechanical control

A. conyzoides is shallow-rooted and relatively easy to control using mechanical means. As it is a prolific seeder, it is important to destroy plants before they flower. 

Chemical control

A wide range of herbicides have been used to control the weed selectively in major crops. Bentazone, butachlor, 2,4-D, MCPA and oxidiazon are effective treatments in rice (Ampong-Nyarko and de Datta, 1991); nicosulphuron is used in maize (Ferreira et al., 1996); cyanazine, metolachlor, metribuzin and cinmethylin are used in soyabean (de Souza, 1988), acetochlor gives good control in maize (Silva et al., 1986); and atrazine and simazine are used in peaches (Gautam and Chauhan, 1984). Metribuzin provides residual control in tea (Satyanarayana et al., 1981) and terbutryne with ametryne are selective in sugarcane (Reddi et al., 1977). Imazethapyr provides effective control in soybean (Angiras and Rana, 1995).

Gaps in Knowledge/Research Needs

Research on the quantitative measurements of the impact of the species on biodiversity is recommended (GISD, 2016).

References

Acevedo-Rodríguez P, Strong MT, 2012. Catalogue of the Seed Plants of the West Indies. Smithsonian Contributions to Botany, 98:1192 pp. Washington DC, USA: Smithsonian Institution. http://botany.si.edu/Antilles/WestIndies/catalog.htm

Adams CD, 1963. Compositae. In: Hutchinson J, Dalziel JM, Hepper FN, eds. Flora of West Tropical Africa, Volume 2, Second edition. London, UK: Crown Agents

Adams CD, Kasasian L, Seeyave J, 1970. Common Weeds of the West Indies. St Augustine, Trinidad: University of the West Indies

Agrawal SK, Agrawal KK, Jain KK, 1995. Effect of herbicides and spacings on weed dynamics in soybean-weed association. World Weeds, 2(2):83-92; 2 ref

Ahanchede A, Gasquez J, 1997. Weeds of rainfed crop fields in northeastern Benin. Agriculture et De^acute~veloppement, May (special issue):17-23; 14 ref

Alva AS, 1973. Manual de las Malezas de al Costa Norperuana. Truijillo, Peru: Universidad Nacional de Truijillo

Ampong-Nyarko K, Datta SK de, 1991. Handbook for weed control in rice. Manila, Philippines: International Rice Research Institute

Angiras NN, Rana MC, 1995. Dose and time of application of imazethapyr for weed control in soybean (Glycine max). Indian Journal of Agronomy, 40(1):59-63

Asthana A, Chandra H, Dikshit A, Dixit SN, 1982. Volatile fungitoxicants from leaves of some higher plants against Helminthosporium oryzae. Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz, 89(8/9):475-479

Auld BA, Medd RW, 1992. Weeds: An Illustrated Botanical Guide to the Weeds of Australia. Melbourne, Australia: Inkata Press

Baker H, 1965. Characteristics and modes of origin of weeds. In: Baker H, Stebbins G, eds. The Genetics of Colonising Species. New York, USA: Academic Press, 147-169

Banda AK, Morris B, 1985. Common Weeds of Malawi. Lilangwe, Malawi: University of Malawi

Barnes DE, Chandapillai MM, 1972. Common Malaysian Weeds and their Control. Kuala Lumpur, Malaysia: Ansul (Malaysia) Sdn. Berhad

Bebawi FF, Neugebohrn L, 1991. A review of plants of northern Sudan with special reference to their uses. A review of plants of northern Sudan with special reference to their uses., 294pp.; [many col. pl., 1 map]; 10 ref

Berhaut J, 1967. Flore du Senegal. Dakar, Senegal: Editions Clairafrique

Bhowmik MK, Chakraborty T, Raha AK, 1999. The habitat and food habits of hog deer (Axis porcinus) in protected areas of sub-Himalayan West Bengal. Tigerpaper, 26(2):25-27; 2 ref

BioNET-EAFRINET, 2016. Invasive plants key and fact sheets. http://keys.lucidcentral.org/keys/v3/eafrinet/index.htm

BOLDS, 2016. Kingdoms of Life being barcoded. BOLD Systems. http://www.boldsystems.org/index.php/TaxBrowser_Home

Bouda H, Tapondjou LA, Fontem DA, Gumedzoe MYD, 2001. Effect of essential oils from leaves of Ageratum conyzoides, Lantana camara and Chromolaena odorata on the mortality of Sitophilus zeamais (Coleoptera, Curculionidae). Journal of Stored Products Research, 37(2):103-109

Boulos L, El-Hadidi MN, 1984. The Weed Flora of Egypt. Cairo, Egypt: The American University in Cairo Press

Centre for Plant Conservation, 2004. USA. http://www.ridgewayb.mobot.org/cpcweb/CPC_viewprofile.asp?.CPCNum=630

Cheema SS, 1991. Ageratum conyzoides Linn. - a new host for yellow vein mosaic virus of bhindi in the Punjab. Plant Disease Research, 6(1):104

Chong KY, Tan HTW, Corlett RT, 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Singapore: Raffles Museum of Biodiversity Research, National University of Singapore, 273 pp. http://lkcnhm.nus.edu.sg/nus/pdf/PUBLICATION/LKCNH%20Museum%20Books/LKCNHM%20Books/flora_of_singapore_tc.pdf

Diamond AR, 2015. Two species rediscovered in Alabama after 100 years. Phytoneuron, 47:1-3

Dogra KS, Kohli RK, Sood SK, Dobhal PK, 2009. Impact of Ageratum conyzoides L. on the diversity and composition of vegetation in the Shivalik hills of Himachal Pradesh (Northwestern Himalaya), India. International Journal of Biodiversity and Conservation, 1(5):135-145. http://www.academicjournals.org/ijbc/PDF/PDF2009/September/Dogra%20et%20al.pdf

Drummond RB, 1984. Arable Weeds of Zimbabwe. Harare, Zimbabwe: Agricultural Research Trust of Zimbabwe

Encyclopedia of Life, 2016. Encyclopedia of Life. http://www.eol.org

Enyinnia T, 1992. Chemical weed control in rainfed upland rice in Nigeria. Tropical Pest Management, 38(4):408-410

Everaarts AP, 1981. Weeds of vegetables in the highlands of Java. Weeds of vegetables in the highlands of Java. Horticultural Research Institute. Pasarminggu, Jakarta Indonesia, 121 pp

Fagoonee I, Umrit G, 1980. Biology of Dysdercus flavidus Sign. and its control by Ageratum conyzoides. Revue Agricole et Sucriere de l'Ile Maurice, 59(3):122-128

Ferreira FA, Silva AA da, Ferreira LR da, 1996. Effectiveness of nicosulfuron, in two formulations, in controlling weeds in maize (Zea mays L.). Ciencia e Agrotecnologia. 20(1):19-24

Flora do Brasil, 2016. Brazilian Flora 2020 in construction. http://reflora.jbrj.gov.br/reflora/listaBrasil/ConsultaPublicaUC/ConsultaPublicaUC.do#CondicaoTaxonCP

Flora of China Editorial Committee, 2016. Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2

Fournet J, Hammerton JL, 1991. Weeds of the Lesser Antilles. Paris, France: Department d'Economie et Sociologie Rurales, Institut National de la Recherche Agronomique

Gautam DR, Chauhan JS, 1984. Possibilities of reducing the soil cultivation by using herbicides in peach nursery production. Journal of Tree Sciences, 3(1/2):99-104

Ghate VS, 1991. Noteworthy plant invasions in the flora of Western Ghats of Maharashtra. Journal of the Bombay Natural History Society, 88(3):390-394

GISD, 2016. Global Invasive Species Database (GISD). http://www.issg.org/database/welcome/

Gonzales GB, Webb ME, 1989. Manual Para la Identificacion y Control de Malezas en el Area Integrada de Santa Cruz. Santa Cruz, Bolivia: Centro Internacional de Agricultura Tropical

Grabandt K, 1985. Weeds of Crops and Gardens in Southern Africa. Johannesburg, South Africa: Seal Publishing

Greuter W, 2016. Occurrence details for Ageratum conyzoides. Compositae (pro parte majore). Euro+Med Plantbase ­ the information resource for Euro­Mediterranean plant diversity [ed. by Greuter, W. \Raab­Straube, E. von]. http://ww2.bgbm.org/EuroPlusMed/PTaxonDetailOccurrence.asp?NameId=117571&PTRefFk=7000000

Hanelt P, Buttner R, Mansfeld R, 2001. Mansfeld's Encyclopedia of Agricultural and Horticultural Crops (except Ornamentals). Berlin, Germany: Springer

Holm LG, Pancho JV, Herberger JP, Plucknett DL, 1979. A geographical atlas of world weeds. New York, USA: John Wiley and Sons, 391 pp

Holm LG, Plucknett DL, Pancho JV, Herberger JP, 1977. The World's Worst Weeds. Distribution and Biology. Honolulu, Hawaii, USA: University Press of Hawaii

Invasive Species South Africa, 2016. Plants A-Z: Flora that is invasive in South Africa. Cape Town, South Africa: Invasive Species South Africa. http://www.invasives.org.za/

IRRI, 1989. Weeds Reported in Rice in South and South East Asia. Manila, Philippines: International Rice Research Institute

Johnson MF, 1971. A monograph of the genus Ageratum L. (Compositae-Eupatorieae). Annals Missouri Botanical Garden, 58:6-88

Jones M, 1994. Weeds of the Gambia. Rotterdam, Netherlands: Balkema

Kabir SE, Chaudhuri TC, Hajra NG, 1991. Evaluation of herbicides for weed control in Darjeeling tea. Indian Agriculturist, 35(3):179-185

Kamalam Joseph, Bridgit TK, 1993. Effect of chemical and integrated weed management in upland rice. Journal of Tropical Agriculture, 31(1):77-80

Kang BH, Kwon YW, Lee HK, 1996. Current status and problem of exotic weeds in Korea. In: Import and Export of Agricultural Products and Plant Quarantine. International Symposium. Suwon, Seoul, Korea: Seoul National University, 101-128

Kasasian L, 1964. Common Weeds of Trinidad. St Agustine, Trinidad: University of the West Indies

Kew Royal Botanic Gardens, 2015. Millennium Seed Bank - Seed List. Richmond, UK: Kew Royal Botanic Gardens. http://apps.kew.org/seedlist/SeedlistServlet

Kohli RK, Batish DR, Singh HP, Dogra KS, 2006. Status, invasiveness and environmental threats of three tropical American invasive weeds (Parthenium hysterophorus L., Ageratum conyzoides L., Lantana camara L.) in India. Biological Invasions, 8(7):1501-1510. http://www.springerlink.com/content/81ju7v98t4707711/fulltext.pdf

Liang WG, Huang MD, Prokopy RJ, 1994. Influence of citrus orchard ground cover plants on arthropod communities in China: a review. Agriculture Ecosystems and Environment, 50(1):29-37

Lind EM, Tallantire AC, 1962. Some Common Flowering Plants of Uganda. London, UK: Oxford University Press

Logan p, Zettler FW, 1984. Susceptibility of Rudbeckia, Zinnia, Ageratum, and other bedding plants to Bidens mottle virus. Plant Disease, 68(3):260-262

Lorenzi H, 1982. Weeds of Brazil, terrestrial and aquatic, parasitic, poisonous and medicinal. (Plantas daninhas de Brasil, terrestres, aquaticas, parasitas, toxicas e medicinais.) Nova Odessa, Brazil: H. Lorenzi, 425 pp

Ma YueFeng, Du XiaoLi, Qin JianLin, Huang HuiYe, Li XueSheng, Liu Gang, 2002. Occurrence and herbicide control of lawn weeds in Guangxi. Southwest China Journal of Agricultural Sciences, 15(1):54-59; 14 ref

Mahmood SK, 1990. Rhizosphere microbes of Asteraceae weeds. Indian Journal of Weed Science, 22(1-2):53-56

Mamaril EC, Alberto RT, 1989. Root-knot nematodes infecting some common weeds in vegetable growing areas of Sicsican. International Nematology Network Newsletter, 6(3):37-39

Marks MK, Nwachuku AC, 1986. Seed-bank characteristics in a group of tropical weeds. Weed Research (Oxford), 26(3):151-157

Marnotte P, 1984. Influence of agro-ecological factors on weed development in a humid, tropical climate. Comptes rendu du 7eme colloque international sur l'ecologie, la biologie et la systematique des mauvaises herbes Paris, France: COLUMA/EWRS, Vol. 1:183-190

McIntyre G, 1991. Weeds of Sugar Cane in Mauritius: Their Description and Control. Reduit, Mauritius: Mauritius Sugar Industry Research Institute

Mishra GC, Bhol BB, 1996. Effect of weed management practices on growth and fibre yield of jute (Corchorus capsularis). Indian Journal of Agronomy, 41(1):132-135; 3 ref

Missouri Botanical Garden, 2016. Tropicos database. St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.tropicos.org/

Moody K, Munroe CE, Lubigan RT, Paller EC Jr, 1984. Major Weeds of the Philippines. Los Baños, Philippines: Weed Science Society of the Philippines, University of the Philippines at Los Baños

Nasution U, 1984. Weeds and Their control in Rubber in North Sumatra and Aceh. Jakarta, Indonesia: Pusat Penelitian and Pengembangan Perkebunan Tanjung Morawa

National Park Service, 2004. World wide web page of National Park Service, South Africa at http://www.parks-sa.co.za/conservation/scientfic.services/Biota/act-covering.html

Ngouajio M, Daelemans A, 1993. Effect of fluazifop and bentazon tank-mixed on weeds and selected legume crops. Tropicultura, 11(1):16-19

NPS, 2004. Alien Plant Invaders of Natural Areas in Florida. World Wide Web p[age at http://www.nps.org/plants/alien/list/d.htm

Ohtsuka T, 1998. A comparative review of early herbaceous stages of secondary succession in temperate and tropical regions. Japanese Journal of Ecology, 48(2):143-157

Oviedo Prieto R, Herrera Oliver P, Caluff MG, et al. , 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 6(Special Issue 1):22-96

Pancho JV, 1986. Weeds of vegetable farms in La Trinidad, Benguet, Philippines. Weed control in tropical crops. Volume II. [edited by Moody, K.] Los Banos, Philippines; Weed Science Society of the Philippines, 1-8

Pancho JV, Vega MR, Plucknett DL, 1969. Some Common Weeds of the Philippines. Laguna, Philippines: Weed Science Society of the Philippines, University of the Philippines at Los Ba±os

Pandey UK, Srivastava AK, Chandel BS, Lekha C, 1982. Response of some plant origin insecticides against potato-tuber moth, Gnorimoschema operculella Zeller, (Lepidopt.: Gelechiidae) infesting solanaceous crops. Zeitschrift für Angewandte Zoologie, 69(3):267-270

Paradkar VK, Sharma TR, Sharma RC, 1998. Water stagnation for control of weeds in Eucalyptus rostrata, Schlecht plantation. World Weeds, 5(1/2):67-68

Parham J, 1958. The Weeds of Fiji. Bulletin 35. Suva, Fiji: Department of Agriculture

Parker C, 1992. Weeds of Bhutan. Weeds of Bhutan., vi + 236 pp

PIER, 2004. Pacific Islands Ecosystem at Risk (PIER). Institute of Pacific Islands Forestry. http://www.hear.org/pier/species/

PIER, 2016. Pacific Island Ecosystems at Risk. Honolulu, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Poudyal A, Adhikari A, 2013. Impact assessment of invasive plant species in selected ecosystems of Bhadaure Tamagi VDC. Nepal. Kathmandu, Nepal: IUCN Nepal, 68 pp. https://cmsdata.iucn.org/downloads/impact_assessment_of_invasive_plant_species_in_selected_ecosystem_of_panchase.pdf

PROSEA, 2016. Plant Resources of South-East Asia. http://uses.plantnet-project.org

PROTA, 2016. PROTA4U web database. Wageningen, Netherlands: Plant Resources of Tropical Africa. http://www.prota4u.org/search.asp

Pu TS, Zeng T, Wei DW, Pan GH, Liao GN, 1990. Investigations on predacious mite resources in Citrus orchards in Guangxi and their utilization. Acta Phytophylacica Sinica, 17(4):355-358

Rafey A, Prasad K, 1995. Influence of weed-management practices in pigeonpea (Cajanus cajan) intercropped with upland rice (Oryza sativa). Indian Journal of Agricultural Sciences, 65(4):281-282; 1 ref

Raj Singh, Patel CS, 1992. Crop weed competition in groundnut under mid altitudes of Meghalaya. Indian Journal of Hill Farming, 5(2):89-93

Rajamani K, Thamburaj S, Thangaraj T, Murugesan S, 1992. Studies on the effect of certain herbicides in rose cv. Happiness. South Indian Horticulture, 40(2):121-122

Ranjit JD, Bhattarai AN, 1988. Crop Weeds and their Control in Nepal. Kathmandu, Nepal: Winrock International/USAID

Reed CF, 1977. Economically important foreign weeds. Potential problems in the United States. Agriculture Handbook No. 498. United States Department of Agriculture. Washington D.C., USA: USDA-ARS

Robertson SA, 1989. Flowering Plants of Seychelles. Kew, UK: Royal Botanic Gardens

Roder W, Keoboulapha B, Phengchanh S, Prot JC, Matias D, 1998. Effect of residue management and fallow length on weeds and rice yield. Weed Research (Oxford), 38(3):167-174; 17 ref

Roder W, Phengchanh S, Keobulapha B, 1997. Weeds in slash-and-burn rice fields in northern Laos. Weed Research (Oxford), 37(2):111-119; 24 ref

Royal Museum for Central Africa, 2016. Prelude Medicinal Plants Database. Tervuren, Belgium: Royal Museum for Central Africa. http://www.africamuseum.be/collections/external/prelude

Saikia LR, Sarma SK, 1996. Phytosociological investigation of the rice field weeds of Duliajan (Assam). Indian Journal of Forestry, 19(1):40-44; 8 ref

Salam MA, 1991. Weed hosts of root knot nematodes in Little Andaman Island. Current Nematology, 2(1):83-84

Sánchez-Monge A, Retana-Salazar A, Brenes S, Agüero R, 2011. A contribution to thrips-plant associations records (Insecta: Thysanoptera) in Costa Rica and Central America. Florida Entomologist, 94(2):330-339. http://www.fcla.edu/FlaEnt/

Sankara Reddi GH, Soundara Rajan MS, Chandrasekhara Naidu V, Ageratum conyzoides L. - a new troublesome weed in sugarcane. Program and Abstracts of Papers, Weed Science Conference and Workshop in India, 1977., Paper No. 151:97-98

Satyanarayana N, Ramachandran K, Sharma VS, 1981. The potential of metribuzin as a broad-spectrum herbicide in tea culture. Tropical Pest Management, 27(3):401-404

Sauerborn E, Sauerborn J, 1984. Plants of cropland in Western Samoa with special reference to taro. Plits, 2(4):1-331

Sauerborn J, 1985. Studies on the segetal flora of taro (Colocasia esculenta (L.) Schott) and on the germination biology of selected weeds of Western Samoa. PLITS (Plant Protection Information Tropics/Subtropics), 3(1):85 pp

Sauerborn J, Koch W, Krage J, 1988. On the influence of light, temperature, depth of burial and water stress on the germination of selected weed species. Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz, Sonderheft, 11:47-53

Scheldeman X, Meylemans B, van Damme P, 1995. Weed distribution in relation to pH and soil texture in the dry and intermediate lowland zones of Sri Lanka. Proceedings, 47th international symposium on crop protection: part I, Gent, Belgium, 9 May 1995. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, 60(2a):235-242

Sharma UC, Choudhury AN, Khan AK, 1994. Effect of integrated weed management on yield and nutrient uptake by rainfed rice (Oryza sativa) in acid soils of Nagaland. Indian Journal of Agronomy, 39(4):553-556

Silori CS, Mishra BK, 2001. Assessment of livestock grazing pressure in and around the elephant corridors in Mudumalai Wildlife Sanctuary, south India. Biodiversity and Conservation, 10(12):2181-2195; 29 ref

Silva JB da, Fonseca LB, Silva JJM, 1986. Biological performance of acetochlor in a maize crop. Resumos, Congresso Nacional de Milho e Sorgo, No.16:21

Singh RD, 1992. Studies on crop weed competition and chemical weed control for rice in Sikkim. Indian Journal of Hill Farming, 5(2):107-111

Singh RP, Ram S, 1990. Effect of weed control methods in direct seeded upland rice. Indian Journal of Weed Science, 22(1-2):86-88

Singh VK, Bajpai RP, 1994. Influence of crop geometry and weed-control method on yield and economics of rainfed soybean (Glycine max). Indian Journal of Agronomy, 39(4):671-673

Souza IFde, 1988. Control of weeds in soyabeans with pre-emergence herbicides under cerrado conditions. Pesquisa Agropecuaria Brasileira, 23(4):363-369

Sridhara S, Nanjappa HV, Thimmegowda S, 1995. Weed flora of mulberry gardens under irrigated conditions of Bangalore, (Karnataka). World Weeds, 2(1):29-32; 2 ref

Stadler J, Mungai G, Brandl R, 1998. Weed invasion in East Africa: insights from herbarium records. African Journal of Ecology, 36(1):15-22; 15 ref

Sunaina V, Kishore V, Shekhawat GS, 1989. Latent survival of Pseudomonas solanacearum in potato tubers and weeds. Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz, 96(4):361-364

The Plant List, 2013. The Plant List: a working list of all plant species. Version 1.1. London, UK: Royal Botanic Gardens, Kew. http://www.theplantlist.org

US Fish and Wildlife Service, 1995. Recovery Plan for the Kauai Plant Cluster. In: Recovery Plan for the Kauai Plant Cluster : US Fish and Wildlife Service.270 pp.

US Fish and Wildlife Service, 2010. 5-Year Review, Short Form Summary: Species Reviewed: Poa mannii (Mann's bluegrass). In: 5-Year Review, Short Form Summary: Species Reviewed: Poa mannii (Mann's bluegrass) : US Fish and Wildlife Service.10 pp.

US Fish and Wildlife Service, 2010. Determination of Endangered Status for 48 Species on Kauai and designation of Critical Habitat: Final Rule. In: Determination of Endangered Status for 48 Species on Kauai and designation of Critical Habitat: Final Rule : US Fish and Wildlife Service.i + 205 pp.

US Fish and Wildlife Service, 2010. Schiedea apokremnos (maolioli). 5-Year Review: Summary and Evaluation. In: Schiedea apokremnos (maolioli). 5-Year Review: Summary and Evaluation : US Fish and Wildlife Service.16 pp.

US Fish and Wildlife Service, 2010. Spermolepis hawaiiensis (no common name). 5-Year Review: Summary and Evaluation. In: Spermolepis hawaiiensis (no common name). 5-Year Review: Summary and Evaluation : US Fish and Wildlife Service.19 pp.

US Fish and Wildlife Service, 2011. 5-Year Review, Short Form Summary: Vigna o-wahuensis (no common name). In: 5-Year Review, Short Form Summary: Vigna o-wahuensis (no common name) : US Fish and Wildlife Service.10 pp.

US Fish and Wildlife Service, 2011. Isodendrion longifolium (aupaka). 5-Year Review: Summary and Evaluation. In: Isodendrion longifolium (aupaka). 5-Year Review: Summary and Evaluation : US Fish and Wildlife Service.28 pp. http://ecos.fws.gov/docs/five_year_review/doc3809.pdf

US Fish and Wildlife Service, 2012. Endangered and Threatened Wildlife and Plants; Endangered Status for 23 Species on Oahu and Designation of Critical Habitat for 124 Species; Final Rule. In: Federal Register , 77(181) : US Fish and Wildlife Service.57648-57862. https://www.gpo.gov/fdsys/pkg/FR-2012-09-18/pdf/2012-19561.pdf

USDA-ARS, 2016. Germplasm Resources Information Network (GRIN). National Plant Germplasm System. Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory. https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomysearch.aspx

USDA-NRCS, 2004. The PLANTS Database, Version 3.5. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov

USDA-NRCS, 2016. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Vernon R, undated. Field guide to important arable weeds of Zambia. Department of Agriculture, Chilanga, Zambia, 151pp

Wang ZR, 1990. Farmland Weeds in China. Beijing, China: Agricultural Publishing House

Waterhouse D F, 1994. Biological Control of Weeds: South-east Asian Prospects. Canberra, Australia: ACIAR

Waterhouse DF, 1993. The Major Arthropod Pests and Weeds of Agriculture in Southeast Asia. ACIAR Monograph No. 21. Canberra, Australia: Australian Centre for International Agricultural Research, 141 pp

Waterhouse DF, 1997. The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. Canberra, Australia: Australian Centre for International Agricultural Research. 93 pp. [ACIAR Monograph No. 44]

Wells MJ, Balsinhas AA, Joffe H, Engelbrecht VM, Harding G, Stirton CH, 1986. A catalogue of problem plants in South Africa. Memoirs of the botanical survey of South Africa No 53. Pretoria, South Africa: Botanical Research Institute

Wezel A, 2000. Weed vegetation and land use of upland maize fields in north-west Vietnam. GeoJournal, 50(4):349-357; 31 ref

Whistler WA, 1983. Weed handbook of Western Polynesia. Schriftenreihe der Deutschen Gesellschaft fnr Technische Zusammenarbeit, 157 pp

Witt, A., Luke, Q., 2017. Guide to the naturalized and invasive plants of Eastern Africa, [ed. by Witt, A., Luke, Q.]. Wallingford, UK: CABI.vi + 601 pp. http://www.cabi.org/cabebooks/ebook/20173158959 doi:10.1079/9781786392145.0000

Zelaya IA, Owen MDK, Pitty A, 1997. Effect of tillage and environment on weed population dynamics in the tropics. CEIBA, 38(2):123-135

Zem AC, Lordello LGE, 1983. Studies on hosts of Radopholus similis and Helicotylenchus multicinctus. Trabalhos apresentados a VII Reuniao Brasileira de Nematologia, Brasilia, DF, 21-25 de fevereiro de 1983. Publicacao No.7. Sociedade Brasileira de Nematologia Piracicaba, SP Brazil, 175-187

Zhou CA, Zou JJ, Huang SD, 1994. The effects of Ageratum interplanting in hilly Citrus orchards in Hunan Province on citrus mite and insect populations. Acta Phytophylactica Sinica, 21(1):57-61

Distribution References

Acevedo-Rodríguez P, Strong M T, 2012. Catalogue of the Seed Plants of the West Indies. Washington, DC, USA: Smithsonian Institution. 1192 pp. http://botany.si.edu/Antilles/WestIndies/catalog.htm

Adams CD, 1963. Compositae. In: Flora of West Tropical Africa, 2 (Second) [ed. by Hutchinson J, Dalziel JM, Hepper FN]. London, UK: Crown Agents.

Agrawal S K, Agrawal K K, Jain K K, 1995. Effect of herbicides and spacings on weed dynamics in soybean-weed association. World Weeds. 2 (2), 83-92.

Ahanchede A, Gasquez J, 1997. Weeds of rainfed crop fields in northeastern Benin. Agriculture et Développement. 17-23.

Alva AS, 1973. (Manual de las Malezas de al Costa Norperuana)., Truijillo, Peru: Universidad Nacional de Truijillo.

Angiras N N, Rana M C, 1995. Dose and time of application of imazethapyr for weed control in soybean (Glycine max). Indian Journal of Agronomy. 40 (1), 59-63.

Auld BA, Medd RW, 1992. Weeds: An Illustrated Botanical Guide to the Weeds of Australia., Melbourne, Australia: Inkata Press.

Banda AK, Morris B, 1985. Common Weeds of Malawi., Lilangwe, Malawi: University of Malawi.

Barnes DE, Chandapillai MM, 1972. Common Malaysian Weeds and their Control., Kuala Lumpur, Malaysia: Ansul (Malaysia) Sdn. Berhad.

Bebawi F F, Neugebohrn L, 1991. A review of plants of northern Sudan with special reference to their uses. Eschborn, Germany: Deutsche Gesellschaft für Technische Zusammenarbeit GmbH. 294 pp.

Berhaut J, 1967. (Flore du Senegal)., Dakar, Senegal: Editions Clairafrique.

BioNET-EAFRINET, 2016. Invasive plants key and fact sheets., http://keys.lucidcentral.org/keys/v3/eafrinet/index.htm

CABI, Undated. Compendium record. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

CABI, Undated b. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

Cheema S S, 1991. Ageratum conyzoides Linn. - a new host for yellow vein mosaic virus of bhindi in the Punjab. Plant Disease Research. 6 (1), 104.

Chong K Y, Tan H T W, Corlett R T, 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Singapore: Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp. https://lkcnhm.nus.edu.sg/app/uploads/2017/04/flora_of_singapore_tc.pdf

Diamond AR, 2015. Two species rediscovered in Alabama after 100 years. In: Phytoneuron, 47 1-3.

Drummond RB, 1984. Arable Weeds of Zimbabwe., Harare, Zimbabwe: Agricultural Research Trust of Zimbabwe.

Enyinnia T, 1992. Chemical weed control in rainfed upland rice in Nigeria. Tropical Pest Management. 38 (4), 408-410.

Everaarts A P, 1981. Weeds of vegetables in the highlands of Java. In: Weeds of vegetables in the highlands of Java. Pasarminggu, Jakarta, Indonesia: Horticultural Research Institute. 121 pp.

Flora do Brasil, 2016. Brazilian Flora 2020 in construction., http://reflora.jbrj.gov.br/reflora/listaBrasil/ConsultaPublicaUC/ConsultaPublicaUC.do#CondicaoTaxonCP

Flora of China Editorial Committee, 2016. Flora of China. In: Flora of China. St. Louis, Missouri and Cambridge, Massachusetts, USA: Missouri Botanical Garden and Harvard University Herbaria. http://www.efloras.org/flora_page.aspx?flora_id=2

Fournet J, Hammerton J L, 1991. Mauvaises Herbes des Petites Antilles. Paris, France: Département d'Économie et Sociologie Rurales, Institut National de la Recherche Agronomique. 214 pp.

Ghate V S, 1991. Noteworthy plant invasions in the flora of Western Ghats of Maharashtra. Journal of the Bombay Natural History Society. 88 (3), 390-394.

GISD, 2016. Global Invasive Species Database (GISD)., http://www.issg.org/database/welcome/

Gonzales GB, Webb ME, 1989. (Manual Para la Identificacion y Control de Malezas en el Area Integrada de Santa Cruz)., Santa Cruz, Bolivia: Centro Internacional de Agricultura Tropical.

Grabandt K, 1985. Weeds of Crops and Gardens in Southern Africa., Johannesburg, South Africa: Seal Publishing.

Greuter W, 2016. Occurrence details for Ageratum conyzoides. Compositae (pro parte majore). In: Euro+Med Plantbase ­ the information resource for Euro­Mediterranean plant diversity, [ed. by Greuter W, Raab-­Straube E von]. http://ww2.bgbm.org/EuroPlusMed/PTaxonDetailOccurrence.asp?NameId=117571&PTRefFk=7000000

Holm L, Pancho J V, Herberger J P, Plucknett D L, 1979. A geographical atlas of world weeds. New York, Chichester (), Brisbane, Toronto, UK: John Wiley and Sons. xlix + 391 pp.

IRRI, 1989. Weeds Reported in Rice in South and South East Asia., Manila, Philippines: International Rice Research Institute.

JOHNSON M F, 1971. A monograph of the genus Ageratum L. Compositae-Eupatorieae. Annals of the Missouri Botanical Garden. 58 (1), 6-88. DOI:10.2307/2394925

Jones M, 1994. Flowering plants of the Gambia. Rotterdam, Netherlands: A.A. Balkema. 104 pp.

Kabir S E, Chaudhuri T C, Hajra N G, 1991. Evaluation of herbicides for weed control in Darjeeling tea. Indian Agriculturist. 35 (3), 179-185.

Kamalam Joseph, Bridgit T K, 1993. Effect of chemical and integrated weed management in upland rice. Journal of Tropical Agriculture. 31 (1), 77-80.

Kang B H, Kwon Y W, Lee H K, 1996. Current status and problem of exotic weeds in Korea. In: Import and export of agricultural products and plant quarantine. '96 International Symposium, Seoul, Korea Republic, 19 May 1996. [Import and export of agricultural products and plant quarantine. '96 International Symposium, Seoul, Korea Republic, 19 May 1996.], Suwon, Korea: Seoul National University, College of Agriculture and Life Sciences. 101-128.

Kasasian L, 1964. Common Weeds of Trinidad., St Agustine, Trinidad: University of the West Indies.

Liang W, Huang M, 1994. Influence of citrus orchard ground cover plants on arthropod communities in China: a review. Agriculture, Ecosystems and Environment (Netherlands). 50 (1, special issue), 29-37.

LIND E M, TALLANTIRE A C, 1962. Some common flowering plants of Uganda. Oxford University Press. 257 pp.

Lorenzi H, 1982. Plantas daninhas de Brasil, terrestres, aquaticas, parasitas, toxicas e medicinais. Nova Odessa, Brazil: H. Lorenzi. 425 pp.

Mahmood S K, 1990. Rhizosphere microbes of Asteraceae weeds. Indian Journal of Weed Science. 22 (1-2), 53-56.

McIntyre G, 1991. Weeds of sugar cane in Mauritius: their description and control. Reduit, Mauritius: Mauritius Sugar Industry Research Institute. 158 pp.

Mishra G C, Bhol B B, 1996. Effect of weed management practices on growth and fibre yield of jute (Corchorus capsularis). Indian Journal of Agronomy. 41 (1), 132-135.

Missouri Botanical Garden, 2016. Tropicos database., St. Louis, Missouri, USA: Missouri Botanical Garden. http://www.tropicos.org/

Moody K, Munroe CE, Lubigan RT, Paller EC Jr, 1984. Major Weeds of the Philippines., Los Baños, Philippines: Weed Science Society of the Philippines, University of the Philippines at Los Baños.

Nasution U, 1984. Weeds and Their control in Rubber in North Sumatra and Aceh., Jakarta, Indonesia: Pusat Penelitian and Pengembangan Perkebunan Tanjung Morawa.

Oviedo Prieto R, Herrera Oliver P, Caluff M G, et al, 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba. 6 (Special Issue No. 1), 22-96.

Pancho JV, Vega MR, Plucknett DL, 1969. Some Common Weeds of the Philippines., Laguna, Philippines: Weed Science Society of the Philippines, University of the Philippines at Los Baños.

Parham J, 1958. The Weeds of Fiji. In: Bulletin 35, Suva, Fiji: Department of Agriculture.

Parker C, 1992. Weeds of Bhutan. Thimphu, Bhutan: National Plant Protection Centre. vi + 236 pp.

PIER, 2004. Pacific Islands Ecosystem at Risk (PIER)., Institute of Pacific Islands Forestry. http://www.hear.org/pier/species/

PIER, 2016. Pacific Island Ecosystems at Risk., Honolulu, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Poudyal A, Adhikari A, 2013. Impact assessment of invasive plant species in selected ecosystems of Bhadaure Tamagi VDC. Nepal., Kathmandu, Nepal: IUCN Nepal. 68 pp. https://cmsdata.iucn.org/downloads/impact_assessment_of_invasive_plant_species_in_selected_ecosystem_of_panchase.pdf

PROTA, 2016. PROTA4U web database., Wageningen, Netherlands: Plant Resources of Tropical Africa. http://www.prota4u.org/search.asp

Pu T S, Zeng T, Wei D W, Pan G H, Liao G N, 1990. Investigations on predacious mite resources in Citrus orchards in Guangxi and their utilization. Acta Phytophylacica Sinica. 17 (4), 355-358.

Rafey A, Prasad K, 1995. Influence of weed-management practices in pigeonpea (Cajanus cajan) intercropped with upland rice (Oryza sativa). Indian Journal of Agricultural Sciences. 65 (4), 281-282.

Rajamani K, Thamburaj S, Thangaraj T, Murugesan S, 1992. Studies on the effect of certain herbicides in rose cv. Happiness. South Indian Horticulture. 40 (2), 121-122.

Ranjit JD, Bhattarai AN, 1988. Crop Weeds and their Control in Nepal., Kathmandu, Nepal: Winrock International/USAID.

Reed C F, 1977. Economically important foreign weeds. Potential problems in the United States. Washington, D.C. USA: United States Department of Agriculture. 746 pp.

Robertson SA, 1989. Flowering Plants of Seychelles., Kew, UK: Royal Botanic Gardens.

Roder W, Phengchanh S, Keobulapha B, 1997. Weeds in slash-and-burn rice fields in northern Laos. Weed Research (Oxford). 37 (2), 111-119. DOI:10.1046/j.1365-3180.1996.d01-6.x

Saikia L R, Sarma S K, 1996. Phytosociological investigation of the rice field weeds of Duliajan (Assam). Indian Journal of Forestry. 19 (1), 40-44.

Salam M A, 1991. Weed hosts of root knot nematodes in Little Andaman Island. Current Nematology. 2 (1), 83-84.

Sauerborn E, Sauerborn J, 1984. Plants of cropland in Western Samoa with special reference to taro. Plits. 2 (4), 331pp.

Scheldeman X, Meylemans B, van Damme P, 1995. Weed distribution in relation to pH and soil texture in the dry and intermediate lowland zones of Sri Lanka. [Proceedings, 47th international symposium on crop protection: part I, Gent, Belgium, 9 May 1995. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen], 60 (2a) 235-242.

Sharma U C, Choudhury A N, Khan A K, 1994. Effect of integrated weed management on yield and nutrient uptake by rainfed rice (Oryza sativa) in acid soils of Nagaland. Indian Journal of Agronomy. 39 (4), 553-556.

Singh R D, 1992. Studies on crop weed competition and chemical weed control for rice in Sikkim. Indian Journal of Hill Farming. 5 (2), 107-111.

Singh R P, Ram S, 1990. Effect of weed control methods in direct seeded upland rice. Indian Journal of Weed Science. 22 (1-2), 86-88.

Singh V K, Bajpai R P, 1994. Influence of crop geometry and weed-control method on yield and economics of rainfed soybean (Glycine max). Indian Journal of Agronomy. 39 (4), 671-673.

Sridhara S, Nanjappa H V, Thimmegowda S, 1995. Weed flora of mulberry gardens under irrigated conditions of Bangalore, (Karnataka). World Weeds. 2 (1), 29-32.

USDA-NRCS, 2004. The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov

USDA-NRCS, 2016. The PLANTS Database. Greensboro, North Carolina, USA: National Plant Data Team. https://plants.sc.egov.usda.gov

Wang Z R, 1990. Farmland Weeds in China. Beijing, China: Agricultural Publishing House.

Waterhouse D F, 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. Canberra, Australia: ACIAR. v + 141 pp.

Waterhouse D F, 1997. The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. In: The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. Canberra, Australia: Australian Centre for International Agricultural Research (ACIAR). vi + 93 pp.

Wells M J, Balsinhas A A, Joffe H, Engelbrecht V M, Harding G, Stirton C H, 1986. A catalogue of problem plants in southern Africa incorporating the national weed list of South Africa. Memoirs, Botanical Survey of South Africa. v + 658pp.

Whistler W A, 1983. Weed handbook of Western Polynesia. In: Schriftenreihe der Deutschen Gesellschaft für Technische Zusammenarbeit, 149pp.

Witt A, Luke Q, 2017. Guide to the naturalized and invasive plants of Eastern Africa. [ed. by Witt A, Luke Q]. Wallingford, UK: CABI. vi + 601 pp. http://www.cabi.org/cabebooks/ebook/20173158959 DOI:10.1079/9781786392145.0000

Zhou C A, Zou J J, Huang S D, 1994. The effects of Ageratum interplanting in hilly Citrus orchards in Hunan Province on citrus mite and insect populations. Acta Phytophylacica Sinica. 21 (1), 57-61.

Links to Websites

Contributors

15/09/2016 Updated by:

Jeanine Vélez-Gavilán, University of Puerto Rico at Mayagüez

Distribution Maps