Xanthium strumarium
(common cocklebur)

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Identity

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Preferred Scientific Name

• Xanthium strumarium L. (1753)

Preferred Common Name

• common cocklebur

Other Scientific Names

• Xanthium abyssinicum Wallr.
• Xanthium brasilicum Velloso
• Xanthium californicum E.L. Greene
• Xanthium canadense Mill., 1768
• Xanthium canavillesii Schouw., 1849
• Xanthium chinense Mill.
• Xanthium echinatum Murray, 1784
• Xanthium indicum Klatt, 1880
• Xanthium italicum Moretti
• Xanthium macrocarpum DC
• Xanthium occidentale Bertol.
• Xanthium orientale L. 1763
• Xanthium pensylvanicum Wallr. 1844
• Xanthium pungens Wallr. 1844
• Xanthium ripicola
• Xanthium sibiricum Patrin ex Widder, 1923
• Xanthium strumarium var. canadense (Mill.) Torr. & A. Gray
• Xanthium varians Greene
• Xanthium vulgare Hill

International Common Names

• English: clotbur; cocklebur; ditchbur
• Spanish: Chayotillo
• French: lampourde glouteron
• Portuguese: bardana-menor

Local Common Names

• Australia: noogoora bur; sheep bur
• Germany: Stachel- Spitzklette
• India: adhisishi; bada gokhru bhakra; chota dhatura
• Italy: lappola comune
• Japan: onamomi
• Malaysia: buah anjang
• Netherlands: ongedoornde stekelnoot
• Pakistan: puth kando
• South Africa: kankerroos
• Taiwan: tsai-er
• Thailand: kachab
• Turkey: siraco out

EPPO code

• XANPU (Xanthium pungens)
• XANST (Xanthium strumarium)

Summary of Invasiveness

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The following summary is from Witt and Luke (2017):

Description

Annual much-branched herb with erect stems (20–150 cm high) without spines; stems stout, green, brownish or reddish-brown, roughly hairy.

Origin

Uncertain, but probably Central and South America.

Reason for Introduction

Bee forage and accidentally as a contaminant.

Invades

Roadsides, wasteland, disturbed land, fallow land, crops, plantations, drainage ditches, savannahs, water courses, lowlands, floodplains and sandy dry riverbeds.

Impacts

Rapidly forms large stands, displacing other plant species. X. strumarium is a major weed of row crops such as soybeans, cotton, maize and groundnuts in many parts of the world, including North America, southern Europe, the Middle East, South Africa, India and Japan. It also has a damaging impact on rice production in Southeast Asia. Cocklebur is also an alternative host for a number of crop pests. X. strumarium burrs lodge in animal hair and in sheep’s wool, reducing the quality and increasing treatment costs. The plants are toxic to livestock and can lead to death if eaten.

Taxonomic Tree

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

Notes on Taxonomy and Nomenclature

Top of page The revised classification of Xanthium taxa by Love and Dansereau (1959) reduced the number of Xanthium species to two: X. strumarium and X. spinosum. The numerous species of Xanthium reported in the literature, other than X. spinosum, are now considered forms of X. strumarium. This is an extremely variable species comprising at least two subspecies (for example, X. strumarium var. canadense) and a group of complexes within each, differing in geographic distribution and bur morphology. There are no sterility barriers between subspecies or complexes (Love and Dansereau, 1959; McMillan, 1974; 1975). All these Xanthium taxa are tetraploid with a chromosome number of 2n = 36 (Love and Dansereau, 1959). The related species X. spinosum is more homogeneous throughout its range than X. strumarium. Hybrids between the two species can occur (Love, 1976).

Description

Top of page X. strumarium is a coarse, erect, branching, annual herb which reproduces solely by seed; stems 30 to 150 cm tall, tough, with short dark streaks or spots and covered with short hairs which give a coarse texture; leaves alternate, triangular-ovate to broadly ovate in shape, 2 to 12 cm long, base often cordate, petiole 2 to 8 cm long, margins irregularly toothed or lobed, both surfaces rough-pubescent; flowers monoecious, male flowers inconspicuous, many-flowered heads 5 to 8 mm across, clustered at the tips of branches or axillaries above the female flowers, female flower heads axillary, greenish, two flowers in the head enclosed by the involucre; fruit, a hard brown, ovoid bur, 1.5 to 2.5 cm long, covered with hooked spines 2 to 4 mm long, and with two terminal beaks, fruits readily stick to clothing and fur, and thus are easily spread; seeds (achenes) black, two in each bur, one above the other (from Holm et al., 1977).

Distribution

Top of page The geographic distribution of X. strumarium extends from latitude 53°N to 33°S (Holm et al., 1977). It is most often found in the temperate zone, but also occurs in subtropical and Mediterranean climates. Love and Dansereau (1959) identified the centre of origin of X. strumarium as Central or South America. The native North American Xanthium taxa originally grew along shores and rivers and the fruits were dispersed by water or occasionally by animals.

Distribution Table

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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.

Habitat

Top of page X. strumarium tolerates a wide variety of soil types and textures and a soil pH range of 5.2 to 8.0, as well as frequent flooding and saline conditions (Weaver and Lechowicz, 1983). It occurs in cultivated fields, along beaches, coastal dunes, watercourses, railway embankments, roadsides, field edges, and waste places. It prefers open communities and will disappear if shaded or crowded (Kaul, 1971). It is not common in mountainous regions.

Habitat List

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Category	Sub-Category	Habitat	Presence	Status
Terrestrial

Hosts/Species Affected

Top of page X. strumarium is a very common weed of many row crops in the temperate and subtropical regions of the world. Some forms of X. strumarium are found only along coastal beaches and watercourses, rather than as weeds of crops.

Host Plants and Other Plants Affected

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Biology and Ecology

Top of page Seed germination and emergence of X. strumarium generally occurs in late spring or early summer. The two seeds within each bur often differ in size and dormancy status, with the larger seed germinating in the spring following production, and the smaller seed germinating a year later (Kaul, 1965). Light is not required for germination and seedlings seldom emerge from seeds lying on the soil surface or from those buried 15 cm or more below the soil surface (Stoller and Wax, 1974). Seed production is strongly correlated with above-ground biomass at the time of floral initiation. Vigorous, open-grown plants can produce from 500 to 2300 burs per plant (Weaver and Lechowicz, 1983). The spiny burs are readily dispersed by adhering to animals, human clothing or other materials, as a contaminant of wool, and by water. Viability of seeds buried in the soil does not generally exceed five years (Weaver and Lechowicz, 1983).

X. strumarium is a short-day plant which generally will not flower under photoperiods longer than 14 hours, although populations vary in critical night length with latitude of origin (Ray and Alexander, 1966; McMillan, 1975). X. strumarium has the C3 pathway of photosynthesis. It is self-compatible and primarily wind-pollinated.

Natural enemies

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Notes on Natural Enemies

Top of page A wide range of herbivores, pathogens and seed predators have been recorded on X. strumarium, however, they do not generally provide complete control.

Impact

Top of page X. strumarium is a major weed of row crops such as soyabeans, cotton, maize and groundnuts in many parts of the world, including North America, southern Europe, the Middle East, South Africa, India and Japan. In 1995, it ranked as the fourth, fifth, sixth and seventh most troublesome weed in soyabean, cotton, maize and groundnut, respectively, across 10 southern states in the USA. Between 1974 and 1995, X. strumarium decreased in importance in maize, soyabean and groundnuts in the southern USA, but increased in cotton (Webster and Coble, 1997). These rankings were based on distribution, abundance and difficulty of control.

In soyabeans, cocklebur has been reported to cause the highest reductions in yield of all annual weeds in both northern and southern production areas of the USA (Stoller et al., 1987). Soyabean yield losses are estimated at 10 to 16% for 0.5 plants of X. strumarium per m of row, 65% for 4 plants and 80% for over 10 plants per m of row, for weeds emerging at the same time as the crop (Stoller et al., 1987; Rushing and Oliver, 1998). Similar yield losses from cocklebur were reported in Ontario, Canada (Weaver, 1991). In Italy, Sartorato et al. (1996) recommended an economic threshold of only 0.05 plants of X. strumarium per square m in soyabeans. In addition to direct yield losses through competition, infestations of X. strumarium decrease soyabean seed quality and harvesting efficiency. One cocklebur per m of row was shown to cause a 7.2% increase in foreign material in harvested soyabeans, a 5.2% increase in seed moisture content, decreased test weight by 58.6 g/L seed, and reduced combine speed (Ellis et al., 1998). The authors recommended use of a pre-harvest desiccant when cocklebur densities exceeded 0.5 plants per m of row.

In cotton in the USA, seed yield losses of 60 to 90 kg/ha (approximately 5%) have been reported from cocklebur growing at a density of one plant per 15 m of row in Mississippi (Snipes et al., 1982). Cotton yield losses from one plant of X. strumarium per 3 m of row varied from 6 to 27% in North Carolina (Byrd and Coble, 1991). The critical period for cocklebur in cotton lasted from 2 to 10 weeks after cotton emergence (Snipes et al., 1987).

In groundnuts, cocklebur has been reported to cause yield losses of 31-39% at a density of 0.5 plants and 88% at 4 plants per m of row in the southern USA (Royal et al., 1997a, b). Cocklebur densities higher than 1 plant per 2 m of row reduced deposition of the fungicide chlorothalonil by 34% (Royal et al., 1997b).

The economic impact of X. strumarium in maize is somewhat lower than for soyabeans, cotton and groundnuts. Yields of maize in Illinois, USA have been reported to decrease by 10% at 1 cocklebur per m of row, to a maximum yield loss of 27% at a density of 4.7 cockleburs per m of row (Becket et al., 1988).

Infestations of X. strumarium can also cause significant yield losses in horticultural row crops (Weaver and Lechowicz, 1983). In snap beans, yield losses of 5 to 50% were reported for densities of X. strumarium ranging from 0.5 to 8 per square m (Neary and Majek, 1990).

X. strumarium also has a detrimental impact on livestock production which has been best documented in Australia, where it is abundant in sheep-grazing regions in the eastern half of the continent in Queensland and New South Wales (Wapshere, 1974; Hocking and Liddle, 1986). The burs lodge in animal hair and sheep wool, and are difficult to remove when the wool is processed after shearing. Contaminated wool requires special treatment and may have a price penalty of 25% or more (Wapshere, 1974). The prickly burs can cause considerable discomfort to animals by clinging to hair on the legs and matting the tails and manes of horses.

X. strumarium also has an economic impact in pastures, where cattle, sheep and pigs may be poisoned by eating young plants. The cotyledons contain a toxic compound, carboxyatractyloside, which is absent in older plants (Weaver and Lechowicz, 1982; Hocking and Liddle, 1986; Martin et al., 1992). Symptoms include vomiting, muscular spasms, liver degeneration and occasionally death.

Cocklebur serves as a host for a number of pathogens of crops. Sunflowers have been reported to be damaged by the rust Puccinia xanthii, commonly found on cocklebur, and by alternaria leaf spot (Alternaria helianthi), also found on cocklebur in North America (Hocking and Liddle, 1986). Cocklebur is reported to be a host for Sclerotinia minor and S. sclerotiorum which contaminate soyabean and discolour seed and result in a lowered price (Hocking and Liddle, 1986). X. strumarium is also an alternate host for the insect Spilosoma obliqua (Lepidoptera) which attacks Egyptian clover in India (Dhaliwal, 1993), and for Colletotrichum capsici, which causes anthracnose on tomato fruit and cotton seedlings in the USA (Mclean and Roy, 1991).

The Xanthium genus is closely related to the Ambrosia (ragweed) genus, and X. strumarium produces large amounts of highly antigenic pollen (Reddi et al., 1980). The glandular hairs on the leaves and stem secrete a substance which causes contact dermititis in allergic individuals (King, 1966).

Threatened Species

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Risk and Impact Factors

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• Competition

Uses

Top of page X. strumarium, has been used for various medicinal purposes, including the treatment of malaria in India (Mitich, 1987; Talakal et al., 1995). The genus name is derived from the Greek root 'Xanthos' which means 'yellow', and the plant may once have been used to produce a dye (Weaver and Lechowicz, 1982).

Uses List

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Materials

• Poisonous to mammals

Medicinal, pharmaceutical

• Traditional/folklore

Similarities to Other Species/Conditions

Top of page X. strumarium resembles X. spinosum, but the latter species has stout, three-pronged spines at the stem nodes and in the leaf axils. X. spinosum is primarily a weed of pastures or meadows, although it may occur as a minor weed of row crops. It is also a native of South America, and its range extends from latitude 50°N to 43°S (Holm et al., 1977). X. strumarium is quite common in Australia, and is also found in parts of North and South America, Europe and the Mediterranean.

Both species are sometimes confused with burdocks (Arctium spp.). The latter are biennials which produce a rosette of large leaves during their first year, and spherical burs densely covered with hooked spines during their second year.

Prevention and Control

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Cultural Control

Seedlings of X. strumarium can be controlled by cultivation, but older plants often produce shoots from axillary buds if the root has not been severed. Adoption of zero or reduced tillage systems can potentially reduce Xanthium populations, because burs seldom germinate on the soil surface (Vencill and Banks, 1994).

Chemical Control

X. strumarium is controlled by many soil-applied and foliar herbicides. In France, Mamarot and Rodriguez (1997) give recommendations for a range of treatments including sulcitrone in maize, amitrole directed in maize, bentazon and fomesafen in soyabeans.

In Brazil, Lorenzi (1984) tabulates susceptiblity to bentazon, dicamba, 2,4-D and glyphosate, but states that the weed is resistant to metolachlor, asulam, butachlor, butylate,cyanazine, linuron, oxadiazon, pendimethalin, trifluralin and vernolate. In Papua New Guinea, Henty and Pritchard (1975) indicate susceptibility to 2,4-D, MCPB, amitrole, ametryne and diuron recommended for broad-leaved weeds, including atrazine, dicamba, metribuzin, bentazon, acifluorfen, and imazethapyr.

Populations resistant to imidazolinones and to the arsenical herbicides MSMA/DSMA have been reported in the USA (Heap, 1997).

Biological Control

Biological control of X. strumarium has been attempted with Alternaria helianthi (Abbas and Barrentine, 1995), and the rust Puccinia xanthii (Julien et al., 1979). Seed predation by the moth, Phaneta imbridana, and the trypetid fly, Euaresta aequalis, in the USA, may provide some control (Hare and Futuyma, 1978; Hare, 1980).

A. helianthi caused necrotic lesions on leaves of A. retroflexus, and resulted in 100% or 67% mortality of plants grown under growth chamber or outdoor conditions, respectively, when applied as a solution of conidia to seedlings (Abbas and Barrentine, 1995). The authors suggested that a phytotoxin could be isolated from A. helianthi and sprayed as a mycoherbicide.

The rust P. xanthii occurs in North America and India and was accidentally introduced into Australia (Hocking and Liddle, 1986). It causes deformation of the leaves, splitting of the petioles and stems, and finally leaf drop, but it has not provided significant large-scale control of X. strumarium.

Seed damage ranged from 0 to 28% for Phaneta imbridana, and from 0 to 42% for Euaresta aequalis, on natural populations of X. strumarium in New York. E. aequalis was introduced into Australia from North America in the 1930's. It became established only in the vicinity of Brisbane, and has not contributed significantly to the control of X. strumarium (Hocking and Liddle, 1986).

As summarized by Julien (1992), additional attempts at biological control have included: the lepidopteran Epiblema strenuana which was introduced from Mexico to Australia in 1984 and became widely established, reducing weed vigour and competiveness; Mecas saturnina (Coleoptera), introduced from N. America to Australia in 1963, but thought to have died out; and Nupserha vexator, introduced from India to Fuji and Australia, without notable success.

References

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Abbas HK, Barrentine WL, 1995. Alternaria helianthi and imazaquin for control of imazaquin susceptible and resistant cocklebur (Xanthium strumarium) biotypes. Weed Science, 43(3):425-428

Anderson JM, McWhorter CG, 1976. The economics of common cocklebur control in soybean production. Weed Science, 24(4):397-400

Beckett TH, Stoller EW, Wax LM, 1988. Interference of four annual weeds in corn (Zea mays). Weed Science, 36(6):764-769; 10 ref

Byrd JD Jr, Coble HD, 1991. Interference of common cocklebur (Xanthium strumarium) and cotton (Gossypium hirsutum). Weed Technology, 5(2):270-278

Dhaliwal JS, 1993. Role of some weeds in the carry-over of Spilosoma obliqua (Walker) to Egyptian clover (Trifolium alexandrinum L.). Journal of Research, Punjab Agricultural University, 30(3-4):168-170

Du ZhenZhu, Xu WenBin, Yan Ping, Wang ShaoShan, Guo YiMin, 2012. Three newly recorded alien invasive plants of Xanthium in Xinjiang. Xinjiang Agricultural Sciences, 49(5):879-886. http://www.xjnykx.periodicals.com.cn

Ellis JM, Shaw DR, Barrentine WL, 1998. Soybean (Glycine max) seed quality and harvesting efficiency as affected by low weed densities. Weed Technology, 12(1):166-173; 24 ref

Hare JD, 1980. Variation in fruit size and susceptibility to seed predation among and within populations of the cocklebur, Xanthium strumarium L. Oecologia, 46(2):217-222

Hare JD, Futuyma DJ, 1978. Different effects of variation of Xanthium strumarium L. (Compositae) on two insect seed predators. Oecologia, 37:109-120

Heap IM, 1997. International Survey of Herbicide-Resistant Weeds. Annual Report, Weed Science Society of America

Henty EE, Pritchard GH, 1975. Weeds of New Guinea and their Control. Lp, Papua New Guinea: Department of Forests, Division of Botany, Botany Bulletin No.7

Hocking PJ, Liddle MJ, 1986. The biology of Australian weeds: 15. Xanthium occidentale Bertol. complex and Xanthium spinosum L. Journal of the Australian Institute of Agricultural Science, 52(4):191-221

Holm LG, Pancho JV, Herberger JP, Plucknett DL, 1991. A Geographic Atlas of World Weeds. Malabar, Florida, USA: Krieger Publishing Company

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

Ibrahim AF, El-Wekil HR, Yehia ZR, Shaban SA, 1988. Effect of some weed control treatments on sesame (Sesamum indicum L.) and associated weeds. Journal of Agronomy and Crop Science, 160(5):319-324

Julien MH, Broadbent JE, Matthews NC, 1979. Effects of Puccinia xanthii on Xanthium strumarium (Compositp). Entomophaga, 24(1):29-34

Kamath MK, 1979. A review of biological control of insect pests and noxious weeds in Fiji (1969-1978). Fiji Agricultural Journal, 41(2):55-72

Kaul V, 1965. Physiological-ecology of Xanthium strumarium L. II. Physiology of seeds in relation to its distribution. Journal of Indian Botanical Society, 44:365-380

Kaul V, 1971. Physiological-ecology of Xanthium strumarium L. IV. Effect of climatic factors on growth and distribution. New Phytologist, 70:799-812

King LJ, 1966. Weeds of the World. Biology and Control. New York, USA: Interscience Publ

Li ChangTian, 2012. Xanthium strumarium L., a newly naturalized species of Xanthium form China. Journal of Jilin Agricultural University, 34(5):508-510. http://xuebao.jlau.edu.cn

Love D, Dansereau P, 1959. Biosystematic studies on Xanthium: Taxonomic appraisal and ecological status. Canadian Journal of Botany, 37:173-208

Martin T, Johnson BJ, Sangiah S, Burrows GE, 1992. Experimental cocklebur (Xanthium strumarium) intoxication in calves. Poisonous plants. Proceedings of the Third International Symposium., 489-494; 16 ref

McLean KS, Roy KW, 1991. Weeds as a source of Colletotrichum capsici causing anthracnose on tomato fruit and cotton seedlings. Canadian Journal of Plant Pathology, 13(2):131-134

McMillan C, 1974. Experimental hybridization in Xanthium strumarium of American complexes with diverse photoperiodic adaptation. Canadian Journal of Botany, 52:849-859

McMillan C, 1975. Experimental hybridization of Xanthium strumarium (Compositae) from Asia and America. 1. Responses of F1 hybrids to photoperiod and temperature. American Journal of Botany, 62(1):41-47

Mohammed AS, Tamrat Bekele, 2010. Forage production and plant diversity in two managed rangelands in the Main Ethiopian Rift. African Journal of Ecology, 48(1):13-20. http://www.blackwell-synergy.com/loi/aje

Neary PE, Majek BA, 1990. Common cocklebur (Xanthium strumarium) interference in snap beans (Phaseolus vulgaris). Weed Technology, 4(4):743-748

Ray PM, Alexander WE, 1966. Photoperiodic adaptation to latitude in Xanthium strumarium. American Journal of Botany, 53:806-816

Reddi CS, Reddi EUB, Bai AJ, Raju KVR, Reddi MS, 1980. The ecology of anther dehiscence, pollen liberation and dispersal in Xanthium strumarium L. Indian Journal of Ecology, 7:171-181

Royal SS, Brecke BJ, Colvin DL, 1997. Common cocklebur (Xanthium strumarium) interference with peanut (Arachis hypogaea). Weed Science, 45(1):38-43; 25 ref

Royal SS, Brecke BJ, Shokes FM, Colvin DL, 1997. Influence of broadleaf weeds on chlorothalonil deposition, foliar disease incidence, and peanut (Arachis hypogaea) yield. Weed Technology, 11(1):51-58; 18 ref

Rushing GS, Oliver LR, 1998. Influence of planting date on common cocklebur (Xanthium strumarium) interference in early-maturing soybean (Glycine max). Weed Science, 46(1):99-104; 28 ref

Sartorato I, Berti A, Zanin G, 1996. Estimation of economic thresholds for weed control in soybean (Glycine max (L.) Merr.). Crop Protection, 15:63-68

Snipes CE, Buchanan GA, Street JE, McGuire JA, 1982. Competition of common cocklebur (Xanthium pensylvanicum) with cotton (Gossypium hirsutum). Weed Science, 30(5):553-556

Snipes CE, Street JE, Walker RH, 1987. Interference periods of common cocklebur (Xanthium strumarium) with cotton (Gossypium hirsutum). Weed Science, 35(4):529-532

Stoller EW, Harrison SK, Wax LM, Regnier EE, Nafziger ED, 1987. Weed interference in soybeans (Glycine max). Reviews of Weed Science, 3:155-181

Stoller EW, Wax LM, 1974. Dormancy changes and the fate of some annual weed seeds in the soil. Weed Science, 22(2):151-155

Tashmatov KhM, 1992. Phytoindication of hydrogenous and haloid landscapes interrelations in Uzbekistan. Problems of Desert Development, 2:51-54

Thanassoulopoulos CC, Biris DA, Tjamos EC, 1981. Weed hosts as inoculum source of Verticillium in olive orchards. Phytopathologia Mediterranea, 20(2/3):164-168

United States Department of Agriculture, 1970. Selected Weeds of the United States. Agriculture Handbook No. 366. Washington DC, USA: USDA

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.

Vencill WK, Banks PA, 1994. Effects of tillage systems and weed management on weed populations in grain sorghum (Sorghum bicolor). Weed Science, 42(4):541-547

Wapshere AJ, 1974. An ecological study of an attempt at biological control of Noogoora burr (Xanthium strumarium). Australian Journal of Agricultural Research, 25(2):275-292

Weaver SE, 1991. Size-dependent economic thresholds for three broadleaf weed species in soyabeans. Weed Technology, 5(3):674-679

Weaver SE, Lechowicz MJ, 1983. The biology of Canadian weeds. 56. Xanthium strumarium L. Canadian Journal of Plant Science, 63(1):211-225

Webb CJ, 1987. Checklist of dicotyledons naturalised in New Zealand. 18. Asteraceae (Compositp) subfamily Asteroidep. New Zealand Journal of Botany, 25(4):489-501

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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

Links to Websites

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Distribution Maps

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