Taxonomic name: Sphagneticola trilobata (L.C. Rich.) Pruski
Synonyms: Acmella brasiliensis Spreng., Acmella spilanthoides Cass., Buphthalmum repens Lam., Buphthalmum strigosum Spreng., Complaya trilobata (L.) Strother, Polymnia carnosa Poir., Polymnia carnosa Poir. var. aspera (Rich.) Poir., Polymnia carnosa Poir. var. glabella (Rich.) Poir., Polymnia carnosa Poir. var. triloba (Rich.) Poir., Seruneum paludosum (DC.) Kuntze, Seruneum trilobatum (L.) Kuntze, Silphium trilobatum L., Sphagneticola ulei O.Hoffm., Stemmodontia trilobata (L.) Small, Thelechitonia trilobata (L.) H.Rob. & Cuatrec., Verbesina carnosa M.Gómez, Verbesina carnosa M.Gómez var. aspera (Rich.) M.Gómez, Verbesina carnosa M.Gómez var. triloba (Rich.) M.Gómez, Wedelia brasiliensis S.F.Blake, Wedelia carnea Rich., Wedelia carnosa Rich. ex Spreng., Wedelia carnosa Rich. var. aspera Rich., Wedelia carnosa Rich. var. glabella Rich., Wedelia carnosa Rich. var. triloba Rich., Wedelia crenata Rich., Wedelia paludicola Poepp. & Endl., Wedelia paludosa DC., Wedelia triloba (Rich.) Bello, Wedelia trilobata (L.) Hitchc.
Common names: ate (Tongan), atiat (Puluwat), creeping ox-eye (English), dihpw ongohng (Pohnpei), Hasenfuss (German), ngesil ra ngebard (Palauan), rosrangrang (Kosrae), Singapore daisy (English), trailing daisy (English), tuhke ongohng (Pohnpei), ut mõkadkad (Marshall Islands), ut telia (Marshall Islands), wedelia (English)
Organism type: herb
Although Sphagneticola trilobata is the accepted name for this species, it is widely known as Wedelia trilobata. Sphagneticola trilobata is native to the tropics of Central America and has naturalised in many wet tropical areas of the world. Cultivated as an ornamental, it readily escapes from gardens and forms a dense ground cover, crowding out or preventing regeneration of other species. In plantations, it will compete with crops for nutrients, light and water, and reduce crop yields.
Creeping, mat-forming perennial herbs; stems rounded, rooting at the nodes, 1-3 (-4)
dm long, the flowering portions ascending, coarsely strigose to spreading hirsute, sometimes
subglabrous. Leaves fleshy, usually 4-9cm long, (1.5-) 2-5cm wide, irregularly toothed or serrate,
usually with a pair of lateral lobes. Peduncles 3-10cm long; involucre campanulate-hemispherical,
ca. 1cm high; chaffy bracts lanceolate, rigid; ray florets often 8-13 per head, rays 6-15mm long;
disk corollas 4-5mm long; pappus a crown of short fimbriate scales. Achenes tuberculate, 4-5mm
long, few achenes maturing in cultivated plants in Hawaii. (Wagner et al, 1990)
agricultural areas, coastland, natural forests, planted forests, range/grasslands, riparian zones, ruderal/disturbed, scrub/shrublands, urban areas
Sphagneticola trilobata has a very wide ecological tolerance range, and seems to be
equally suited to dry and moist sites. Although it seems to prefer and do best in
sunny sites, it survives very well in shady sites. It grows well on almost all soil
types, including bare limestone and nutrient poor sandy beaches and swampy or
waterlogged soils. It is tolerant to inundation and high levels of salinity (Thaman, R.R. 1999).
Wedelia is found in open areas with well-drained, moist soil up to 700m or more in elevation (up to 1300m in French Polynesia). It can tolerate dry periods. A noxious weed in agricultural areas, along roadsides and trails, in open lots, wasteplaces and garbage dumps and other disturbed sites. Also naturalized and invasive along streams, canals, along the borders of mangroves and in coastal strand vegetation (PIER, 2003).
If Sphagneticola trilobata becomes established in plantations, it will compete with crops for nutrients, light and water, and reduce crop yields. It rapidly escapes from gardens to roadsides and plantations, where it can overgrow plants and develop into a thick cover (Niue DAFF, 2001).
Forms a dense ground cover, crowding out or preventing regeneration of other species (PIER, 2003).
Used commonly as an ornamental plant and groundcover.
Although Sphagneticola trilobata is the accepted name for this species, it is widely known as Wedelia trilobata.
Native range: Central America.
Known introduced range: American Samoa, Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Caroline outer islands, Fiji, French Polynesia, Guam, Hawai‘i, Marshall Islands, Midway Atoll, Nauru, Niue, Palau, Papua New guinea, Samoa, Tonga, Australia, Indonesia and Christmas Island.
Introduction pathways to new locations
For ornamental purposes: Brought from Hawaii to Pohnpei by women down at the Catholic mission around 1970 who thought it would look nice in their gardens.
Internet sales/postal services: Advertised on the internet as a good "cover". (Tropilab® Inc)
Landscape/fauna "improvement": Introduced to many places as good groundcover.
Local dispersal methods
For ornamental purposes (local): Cultivated as an ornamental, (PIER, 2003).
Garden escape/garden waste: Commonly spread by dumping of garden waste, (PIER, 2003).
Preventative measures: It is suggested that planting of this species be banned, except where it can be contained, and
that dumping of garden waste on vacant lots be prohibited.
A Risk Assessment of Sphagneticola trilobata (Wedelia trilobata) for Hawai‘i and other Pacific islands was prepared by Dr. Curtis Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service. The alien plant screening system is derived from Pheloung et al. (1999) with minor modifications for use in Pacific islands (Daehler et al. 2004). The result is a score of 13 and a recommendation of: "Likely to cause significant ecological or economic harm in Hawai‘i and on other Pacific Islands as determined by a high WRA score, which is based on published sources describing species biology and behaviour in Hawai‘i and/or other parts of the world."
A Risk assessment of
Sphagneticola trilobata (Wedelia trilobata) for Australia was prepared by Pacific Island Ecosystems at Risk
(PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score
of 6 and a recommendation of: reject the plant for import (Australia) or species likely to
be a pest (Pacific).
Physical: The Land for Wildlife program south-east Queensland, recommends 'scarifying' for small patches of soil dominated by weeds like wedelia - the top few centimetres of soil are removed using a suitable tool such as a fire hoe. The aim is to remove soil-stored seed. Do not leave disturbed area open for reintroduction of weeds. Mowing or slashing of wedelia infested areas should be avoided as this may cut the plants into smaller pieces that can develop into new plants, and increases the risk of spreading to new areas, (Liebregts, 2001).
Chemical: Langeland and Stocker (2000), suggest treating small patches with 2% Roundup; and large, dense populations by broadcast-spraying 5% Roundup (with follow-up treatments as needed). Or 1/4-1.0% Garlon 4 in water.
Although it seems to prefer and do best in sunny sites, it survives very well in shady sites also. It grows well on almost all soil types, including bare limestone and nutrient poor sandy beaches and swampy or waterlogged soils. It is tolerant to inundation and high levels of salinity (Liebregts, 2001).
Usually vegetatively. Stems form new plants where they touch the ground and pieces readily take root. Plants usually develop few fertile seeds. Commonly spread by dumping of garden waste, (PIER, 2003).
This species has been nominated as among 100 of the "World's Worst" invaders
Compiled by: IUCN SSC Invasive Species Specialist Group
Updates with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
Last Modified: Monday, 4 October 2010