Sphagneticola trilobata
(wedelia)

Pictures

Picture	Title	Caption	Copyright
Title Foliage Caption Sphagneticola trilobata; dense foliage and flowers. Copyright ©A.R. Pittaway	Foliage	Sphagneticola trilobata; dense foliage and flowers.	©A.R. Pittaway
Title Flower Caption Sphagneticola trilobata; single flower and foliage. Copyright ©A.R. Pittaway	Flower	Sphagneticola trilobata; single flower and foliage.	©A.R. Pittaway
Title Habit Caption Sphagneticola trilobata grown as roadside ground cover adjacent to a rubber plantation. Central Sri Lanka. Copyright ©Chris Parker/Bristol, UK	Habit	Sphagneticola trilobata grown as roadside ground cover adjacent to a rubber plantation. Central Sri Lanka.	©Chris Parker/Bristol, UK

Identity

Preferred Scientific Name

• Sphagneticola trilobata (L.) Pruski

Preferred Common Name

• wedelia

Other Scientific Names

• Acmella brasiliensis Spreng
• Acmella spilanthoides Cass.
• Buphthalmum procumbens Desf. Ex Steud
• Buphthalmum repens Lam.
• Complaya trilobata (L.) Strother
• Sereneum trilobata (L.) Kuntze
• Silphium trilobatum L.
• Sphagneticola ulei O. Hoffm.
• Stemmodontia carnosa (Rich.) O.F. Cook & G.N. Collins
• Thelechitonia trilobata (L.) H. Rob & Cautrec.
• Verbesina carnosa (Rich.) M. Gómez
• Verbesina tridentata Sprengel
• Wedelia brasiliensis (Spreng.) S.F. Blake
• Wedelia carnosa Rich. ex Pers.
• Wedelia trilobata (L.) A.S. Hitchc.
• Wedelina paludosa DC.

International Common Names

• English: Bay Biscayne creeping-oxeye; creeping daisy; creeping ox-eye; creeping wedelia; gold-cup; rabbit's paw; Singapore daisy; trailing daisy; water zinnia; wild marigold; yellow dots
• Spanish: clavelín de playa; clavelito de muerto; clavellin (Panama); manzanilla; manzanilla de playa; margarita amarilla; margarita de pasto; romerillo; romerillo; saladillo macho; yerba buena cimarrona
• French: patte canard
• Chinese: nan mei peng qi ju

Local Common Names

• Bahamas: trailing wedelia
• Brazil: insulin; vedélia
• Cuba: romero de playa
• Germany: Wedelie, Goldstern-
• Jamaica: creeping oxeye
• Lesser Antilles: bobena; carpet daisy; graveyard daisy; graveyard grass; herb soleil; lad love; pa a kanna; pasture sage; piss weed; venvenn kawayib; verven carib; vin vin caribe; yellow marigold; zeb a fan
• Marshall Islands: ut mokadkad; ut telia
• Micronesia, Federated states of: atiat; dihpw ongohng; dihpwoangoahng suwed (Pohnpei); rostangrang; tuhke ongohng
• Palau: ngesil ra ngebard
• Saint Lucia: venvenn kawayib
• South Africa: Singapoer-madeliefie
• Tonga: ate
• USA: Bay Biscayne creeping oxeye; yellow dots

EPPO code

• WEDTR (Wedelia trilobata)

Summary of Invasiveness

S. trilobata has spread rapidly threatening the native flora after introduction as an ornamental species. It can spread vegetatively and is difficult to eradicate. The IUCN has listed S. trilobata in its 100 of the world's worst invasive alien species and the Florida Exotic Plant Pest Council classified it as a category II invader. This species continues to be available as an ornamental and is therefore likely to spread further.

Taxonomic Tree

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

Notes on Taxonomy and Nomenclature

The basonym is Siphium trilobatum L., and the species has since been transferred to numerous genera including Compalaya,Sphagneticola, Thelechitonia, Verbesina and Wedelia. Although Sphagneticolatrilobata is the accepted name (HEAR, 2008, USDA-NRCS, 2008; Missouri Botanical Garden, 2008; USDA-ARS, 2008), Wedeliatrilobata is still widely used in the Pacific (HEAR, 2008), the USA and elsewhere. A large number of other synonyms are provided by Missouri Botanical Garden (2008).
 

Description

S. trilobata is perennial and grows to 45-60 cm high. Stems are green, rounded, rooting at nodes, 10-30 cm long, the flowering portions ascending, coarsely strigose to spreading hirsute, sometimes subglabrous. Leaves are medium textured, fleshy, usually 4-9 cm long (1.5-) 2-5 cm wide, simple obovate, irregularly toothed or serrate, usually with a pair of lateral lobes. The leaf arrangement is opposite to subopposite. Leaf venation is bowed and brochidodrome. Leaves are green in colour and do not change colour during autumn in the USA. S. trilobata usually flowers throughout the year. Flowers, solitary, arise in the leaf axils at any height but appear to have the most blossoms at about 10 cm above ground level. Peduncles 3-10 cm long, involucre, campanulate-hemispherical, 1 cm high; chaffy bracts lanceolate, rigid, ray florets often 8-13 per head, yellow in colour, rays 6-15 mm long; disk corolla 4-5 mm long; pappus a crown of short fimbriate scales (HEAR, 2008). Achenes tuberculate, 4-5 mm long with a brown, dry and hard fruit cover. Fruits are inconspicuous.

Distribution

S. trilobata is native to tropical America, from Mexico to Brazil including much of the Caribbean (USDA-ARS, 2008). It is now also common in many other parts of the world, especially at low elevations. S. trilobata is also present in West Africa, though records are limited. It has a history of repeated introductions outside its natural range and is becoming widely naturalized throughout the tropics (HEAR, 2008).

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

S. trilobata has been repeatedly introduced to other countries as an ornamental plant although the original dates of introduction are rarely known. GBIF (2008) lists earliest herbarium specimens in Australia from the mid 1980s, Hong Kong in 1993 and both Papua New Guinea and Indonesia as recently as 1997. Propagules are intentionally dispersed because S. trilobata is one of the most common and dependable ground covers in landscaping and it has been commonly introduced to many tropical gardens as an ornamental and has spread from these foci.

Risk of Introduction

Further spread of S. trilobata is highly probable, due to risks of accidental movement, mixed with crop seeds and other agricultural produce, and in soil. Deliberate introduction of this species to natural habitats is also very common because S. trilobata has an ornamental value in landscape practices. It is available from dozens of internet plant sales sites and is therefore certain to reach many new territories in the future.

Habitat

S. trilobata grows well in open areas up to 700 m or more in elevation (and up to 1300 m in French Polynesia) although it is commonly a coastal species. It is a noxious weed in agricultural areas, along roadsides and trails, in open areas, waste ground, irrigated lawns, rubbish dumps, natural grasslands and disturbed sites. Thaman (1999) has reported that S. trilobata has become naturalized in many Pacific islands and has become invasive along streams, canals, the margins of mangrove forests and in coastal vegetation. S. trilobata is suited to a wide variety of conditions and will cover rough rocky ground or wet drainage ditches and even tolerates some degree of trampling.

 

Habitat List

Hosts/Species Affected

S. trilobata is a threatening invasive species in agricultural and forestry land, urban areas and roadsides. It forms a dense ground cover, crowding or preventing regeneration of other species (HEAR, 2008). It has been reported as a weed of taro (Colocasia esculenta) in Fiji (Macanawai, 2013).

Growth Stages

Biology and Ecology

Genetics

The chromosome number for S. trilobata is given as x=30, 2n=60 by the Missouri Botanical Garden (2008). Ren et al. (2012) give the karyotype formula 2n=56=24m+28sm+4st, and postulate that the basic chromosome number may be x=14 rather than x=15 and that S. trilobata may be tetraploid.

Wu et al. (2013) report that S. trilobata in South China, where it is invasive, may be hybridizing with the native congener Sphagneticola calendulacea.

Reproductive Biology

S. trilobata produces achenes which contain seeds that are often said to be sterile (Hear, 2008), however, Macanawai (2013) demonstrated that large numbers of seeds were present in the the soil seed bank in wedelia-infested study sites in Fiji and that up to 17% of seeds were viable. The minimum generative time of these seeds is usually one year. However, S. trilobata usually propagates vegetatively, with stems forming new plants where they touch the ground. Stem fragments also readily form roots.

Physiology and Phenology

S. trilobata is a vigorous perennial herb capable of forming a continuous herbaceous ground cover. Flowering takes place year round. It produces the most flowers in open, frost-free locations. However, S. trilobata can grow in shade and still flower, although only sparingly. Where it has escaped from garden boundaries it can be found in lawns and disturbed areas, where it will respond to mowing by flowering at ground level.

Environmental Requirements

S. trilobata is generally a tropical species which will thrive in full sun or shade, but full sun produces most flowering. It grows in any soil when provided with ample moisture, but is also moderately drought tolerant and can tolerate extended flooding. It grows best in moist, well-drained, fertile soils, clays, sands or loams and can tolerate saline soils. S. trilobata does well over a range of soil pH values, but 5.5-7.5 is preferred. Though killed to the ground by frost when grown in temperate countries, S. trilobata may return with the onset of warm weather in the spring. The long, creeping stems of S. trilobata root wherever they touch moist soil.

In China, S. trilobata has been reported to grow better at high temperatures and carbon dioxide levels than its indigenous related species Wedelia chinensis, and it is suggested that the invasive species may become more aggressive through climate change (Song et al., 2010a,b).

Climate

Latitude/Altitude Ranges

Air Temperature

Rainfall

Notes on Natural Enemies

Though relatively resistant to many pests, S. trilobata can occasionally be infested with chewing insects, leaf hoppers and mites. These insects are seldom fatal to S. trilobata, and chemical pest controls are only recommended for severe infections. In Hawaii, it has been reported that the banana rind thrip, Elixothrips brevisetis, feeds on leaves, flowers and stems of S. trilobata, with injured tissue taking on a silvery appearance and eventually turning dark brown. When E. brevisetis feeds on the leaf tips it results in wilting and curling and the undersides of leaves are spotted with small black faecal specks. Flowers become flecked, spotted, deformed and many buds fail to open. This thrip causes scarring and the formation of corky growth on fruit skins (Metcalf et al., 1962; Muruvanda, 1986). Several leaf spot and root rot diseases also affect the growth and development of S. trilobata under moist conditions.

Yu et al. (2011) report that native Cuscuta australis reduces the growth and nutrient content of invasive hosts including S. trilobata, helping native species to compete against the invader.

Means of Movement and Dispersal

S. trilobata usually reproduces vegetatively (HEAR, 2008) but viable seeds may also be present in the soil (Macanawai, 2013). The propagules are very often dispersed intentionally by people, or unintentionally in garden waste. It is commonly planted as an ornamental (Englberger, 2009).

Plant Trade

Impact Summary

Economic Impact

There are costs associated with the control of S. trilobata in agricultural situations, though no figures are available. It is listed as a ‘principal’ weed in Trinidad (Holm et al., 1991). In Sri Lanka, it is a favoured host of Cuscuta campestris and could therefore contribute to the spread of this serious parasitic weed (Jayasinghe et al., 2004).

Environmental Impact

Impact on Habitats

S. trilobata is an aggressive weed which forms a dense ground cover. This plant will spread rapidly excluding other ground cover vegetation. It has a vine-like habit and grows up into shrubs and trees thus retarding their growth. Batianoff and Franks (1997) reported that S. trilobata invaded the sandy beach fronts along the east coast of Queensland in Australia. Competition with other vegetation may be enhanced by allelopathic effects (Zhang et al., 2004), and the same allelopathic substances may also damage brine shrimps (Nie et al., 2004).

Impact on Biodiversity

S. trilobata has been ranked as a threatening invasive species that has invaded and affected the native biota of many areas in Hawaii, many other Pacific islands, the West Indies and southern Florida, USA, Central America, West Africa and Asia. In addition, it will also invade rainforest margins. The regeneration of native species in invaded areas can be inhibited due to rapid growth of S. trilobata and this can lead to reduction of biodiversity in invaded areas.

In South China, S. trilobata hybridization with the native congener Sphagneticola calendulacea is reported to threaten conservation of the native species (Wu et al., 2013).
 

Social Impact

S. trilobata has an ornamental value. Subramanium (1996) reported that it could be maintained on fences, arches, compounds, building walls, trees, pillars and roofs to provide aesthetic appeal.

Risk and Impact Factors

• Invasive in its native range
• 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
• Pioneering in disturbed areas
• Long lived
• Fast growing
• Has propagules that can remain viable for more than one year
• Reproduces asexually

• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Monoculture formation
• Negatively impacts agriculture
• Negatively impacts forestry
• Negatively impacts tourism
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of endangered species

• Allelopathic
• Competition - monopolizing resources
• Competition - smothering
• Interaction with other invasive species
• Rapid growth

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

Uses

S. trilobata provides an excellent ground cover and is especially good for soil retention and erosion control. Farmers in Indonesia believe it enhances soil fertility (Handayani et al., 2006). S. trilobata is very attractive because of nearly constant and prolific blooming of yellow daisy-like flowers. Therefore it is used in many landscape practices and mass planting such as under trees, open areas, around rocks and ponds as a covering in parkways and on walls or in pots. Furthermore, this species is excellent for erosion control on slopes and banks because it roots where the stems come in contact with soil. S. trilobata can also be used successfully as a companion crop to combat silver leaf whitefly (Bemisia tabaci), an important vegetable pest in Puerto Rico, the southern USA and the Caribbean Basin.

S. trilobata has traditionally been used to treat infections, indigestion and to treat hepatitis. It shows considerable anti-hepatotoxic and protective effects against carbon tetrachloride induced liver destruction. The active ingredient present in S. trilobata is a coumestan called wedelolactone (Wagner et al., 1986). Due to the presence of active chemicals such as n-hexane and ethyl acetate in extracts of S. trilobata, it shows antibacterial activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus, Staphylococcus epidermidis, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella group C, Salmonella paratyphi and Shigella sonnei (Taddei and Romero, 1999). S. trilobata has also been traditionally used to clear the placenta after birth. Sureshkumar et al. (2007) also report effectiveness as an analgesic in studies on mice.

Dissanayake et al. (2002) reported that S. trilobata has the capability to absorb a high amount of Cu+2, Ni+2, Mn+2 and Fe+2 / Fe+3 from polluted areas in Sri Lanka. Hence, S. trilobata can be recommended as a phyto-remediator that can be used in a profitable manner to treat waste effluents and environments contaminated with heavy metal ions.

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.

Cultural Control

Growth of S. trilobata can be controlled by carefully managing nitrogen fertilizer and irrigation. The importation and spread of S. trilobata can be significantly reduced by public education on the aggressive nature of the species. Educating the public on the identity, impacts and control of the spread of S. trilobata can reduce ecological degradation of native ecosystems by S. trilobata.

Mechanical Control

S. trilobata can be effectively controlled by removing the top few centimetres of soil using a suitable tool such as a fire hoe (a sharped-toothed hoe used for cutting roots and sod to clear fire breaks), with the aim of removing the soil-stored seed bank. Studies have shown that hand pulling can be effective, but can be impractical on a larger scale, because even small underground portions can re-sprout and seeds buried in soil can germinate. Therefore, repeated hand pulling or follow up with herbicide application is often necessary. In addition, burning can also be practised. It is important to note that pulling plants from the ground may cause unwanted soil disturbance in certain areas and recolonization by other invasive non-native plants. Hence, plans for management or replanting of sites with native vegetation should be carefully developed prior to implementation of mechanical removal.

Chemical Control

The spread of S. trilobata may be controlled by spraying metsulfuron-methyl herbicide (HEAR, 2008) and the addition of a suitable wetting agent is also important. This gives good control, but it is important to follow up with repeat treatments as some underground runners will survive the initial treatment and resprout (HEAR, 2008). In Australia, Spencer (2012) reports that most native species growing together with S. trilobata in the Daintree, Queensland, are resistant to metsulfuron-methyl and that native sensitive species tended to be pioneer species which could readily colonise once S. trilobata had been removed.

Large, dense populations may be treated by tryclopyr ester with follow-up treatments as needed. Spread of S. trilobata can also be controlled by applying 2,4-D, dicamba or triclopyr because many broadleaved weed species are more sensitive to these herbicides than are grasses. Also, some chemical growth regulators have shown promise in controlling the height of S. trilobata.

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Links to Websites

Contributors

10/07/13 Updated by:

Julissa Rojas-Sandoval, Department of Botany-Smithsonian NMNH, Washington DC, USA

Pedro Acevedo-Rodríguez, Department of Botany-Smithsonian NMNH, Washington DC, USA

15/04/2008 Updated by:

Chris Parker, Consultant, UK

Distribution Maps