Lantana camara (Lantana)

Scientific name

Lantana camaraL.

Synonyms

L. aculeata L.; Camara vulgaris Benth.; Lantana armata Schauer; Lantana scabrida Sol.; Lantana tiliifoliaCham.

Common names

Lantana, tick berry, Spanish flag, magwagwa (Luo), mjungwina (Shambaa), mukenia (Kikuyu), nyabend-winy (Luo), omuhuuki (Ankole)

Family

Verbenaceae

Origin

Native to Mexico, Central America, the Caribbean and tropical South America.

Naturalised distribution (global)

Locations within which Lantana camara is naturalised include Africa, Australia, India, south-eastern Asia and many oceanic islands with warm climates.

Introduced, naturalised or invasive in East Africa

Lantana camara is invasive in large parts of Kenya, Tanzania and Uganda (Lyons and Miller 1999). It is very widespread in all three countries.

Habitat

Lantana camara occurs along roadsides, in degraded lands, in riparian zones (banks of watercourses), along fence lines and in  pastures and parklands, in plantations, forest edges and gaps and is now seen invading native vegetation in woodlands and savannas (notably in protected areas).

Description

A much-branched, upright (erect), arching or scrambling shrub that usually grows 2-4 m tall and forms dense thickets. It can occasionally grow like a vine (as a scandent shrub) due to its patterns of short branches and if there is support by other vegetation, in which case it can reach up to 15 m in height.

The young stems are usually green and square-shaped (quadrangular) in cross-section. They are rough to the touch, often armed with short prickles, and can be hairy. As they mature the stems become rounded and turn grey or brown in colour. In some wild varieties the stems are armed with small or large spines, in others they are smooth.  The leaves are simple and oppositely arranged along the stem. They have leaf stalks (petioles) that are 5-30 mm long and a crenate or serrated (toothed) margin. The leaf blades are mostly egg-shaped in outline with broad end at base (ovate) and are 2-12 x 1.5-7 cm in size. The texture of the leaf is quite rough (scabrous), however, the underside can be softly hairy.

Its dense flower clusters consist of numerous small tubular flowers (9-14 mm long and 4-10 mm across). These flower clusters are borne on stalks originating in the leaf forks. The flowers can be a wide variety of colours (white, cream, yellow, orange, red, pink, purple and are usually made up of three circles of florets - each one commonly of a different colour (except in some cultivated varieties bred to have single colours) . There are over 100 different combinations of flower colours in wild varieties. The fleshy fruit is glossy in appearance and black, purplish-black or bluish-black when mature, 3-6 mm in diameter containing 1-2 seeds (1.5 mm long). Flowering and fruiting throughout the year with a peak during the first two months of the rainy season.

Reproduction and dispersal

This plant  reproduces by seeds, which are readily dispersed by birds and other animals (e.g. rodents) that eat the fruit. Existing colonies may also spread laterally via the production of suckers or when branches take root after coming into contact with the soil (by layering). Stem fragments or pieces of the rootstock (crown) can also give rise to new plants after being moved by machinery or dumped in garden waste.

Similar species

Creeping lantana (Lantana montevidensis) is a closely related species but has a creeping (prostrate) growth habit. Also, this species does not have prickles or thorns and the weedy forms have purple flowers. There are also similar looking native species such as Lantana trifolia and Lippia species that may look similar to Lantana camara.

Economic and other uses

Many weedy and non-weedy cultivars of this species are grown as ornamentals and as hedges in Kenya, Tanzania and Uganda. The stems can be used to make artisanal products such as carrying cages for chickens and other items that required bendable stems for construction. However, these uses cannot compensate for this plant's overall negative impacts.

Environmental and other impacts

Lantana camara is one of the most problematic invasive plants in many parts of the world. It is probably the most widespread terrestrial invasive plant in Africa.

L. camara forms extensive, dense and impenetrable thickets in forestry plantations, orchards, pasture land, waste land and in natural areas. The rapid spread of L. camara is associated with human induced disturbance. However, it can also invade forest gaps. In areas where natural fires occur they stimulate thicker regrowth. The fallen leaves produce allelopathic substances that prevent other plants germinating and growing beneath L. camara which results in no understory below the thickets and a "monoculture" of the alien plant which continues to spread and adapt to drier conditions  as well as invading medium to high rainfall areas in East Africa.  Rapid spread is also characteristic of wild L. camara in East Africa such that many hundreds of hectares of both productive grazing and protected grasslands/woodlands have been observed to become heavily invaded with a few years of first infiltration from roadside infestations (G.W. Howard pers.com.).

Its extensive seed production favours rat populations. In New Caledonia, by increasing fire intensity as a result of its large dry biomass as well as its smothering effect, it displaces natural scrub communities (Sharma et al. 1988).

L. camara is poisonous to livestock and children have been known to die after eating unripe berries. It is also unpalatable, and in large doses (approximately 1% of total body weight) is poisonous, particularly to cattle.  If untreated L. camara poisoning can result in photosensitisation, loss of appetite, jaundice, liver and other organ/tissue damage, and even death (Queensland Government, 2003).  In Australia it is also considered a serious weed of the plantation timber and orchard industries (Swarbrick et al., 1998). The value of lost production from the Australian grazing sector resulting from the presence of lantana is expected to be approximately $46.2 million annually.  Most of the pasturelands in India have been invaded to some or other degree resulting in lost productivity of approximately US$924 million per year (Pimentel et al., 2001).  It would not be unreasonable to state that L. camara significantly reduces the potential agricultural output in Africa.

L. camara has been nominated as among 100 of the "World's Worst" invaders by the IUCN Invasive Species Specialist Group and it has been listed as a noxious weed in many countries and states including South Africa (prohibited plants that must be controlled. They serve no economic purpose and possess characteristics that are harmful to humans, animals or the environment) and Australia.

Management

The best form of weed control is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response).

Attempts to control Lantana camara using large grazers are detrimental. Few large browsers are entirely freed from the plants ability to cause ulcers and other lesions, especially around and in their mouths. Mechanical control can be effective but there must be continuous follow-up as stem and roots freely coppice. Burning can encourage lantana regeneration. Work carried out in the South African Kruger National Park by Erasmus et al. (1993) showed that chemical control was cheaper and caused less disturbance resulting in higher biodiversity than mechanical control.  When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.

Biological control has been attempted in many parts of the tropics with varying degrees of success as different cultivars display differences in susceptibility to insect herbivores. However it is generally accepted that biocontrol is the only long-term and sustainable method of L. camara control and a suite of agents is available (once approved for introduction and release).

Legislation

Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.

References

CABI Invasive Species Compendium online data sheet. Lantana camara (lantana). CABI Publishing 2011. www.cabi.org/ISC. Accessed March 2011.

Erasmus., D.J., Maggs, K.A.R., Biggs, H.C., Zeller, D.A. and Bell, R.S. (1993). Control of Lantana camara in the Kruger National Park, South Africa, and subsequent vegetation dynamics. Brighton crop protection conference, weeds. Proceedings of an international conference, Brighton, UK, 22-25 November 1993 Farnham, UK; British Crop Protection Council (BCPC), Vol. 1:399-404.

Global Compendium of Weeds. www.hear.org/gcw. Hawaiian Ecosystems at Risk Project. Accessed March 2011.

GISD (2006). Global Invasive Species Database online data sheet. Lantana camara (shrub). www.issg.org/database. Accessed March 2011.

Henderson, L. (2001).  Alien weeds and invasive plants. A complete guide to declared weeds and invaders in South Africa.  Plant Protection Research Institute Handbook No. 12, 300pp. PPR, ARC South Africa.

Lyons, E.E. and Miller, S.E. (eds) (1999). Invasive Species in Eastern Africa: Proceedings of a Workshop held at ICIPE, July 5-6, 1999.

Morton J.F. (1994). Lantana, or red sage (Lantana camara L., [Verbenaceae]), notorious weed and popular garden flower; some cases of poisoning in Florida. Econ. Bot. 48: 259-270.

Sharma, O.P., Makkar, H.P.S. and Dawra, K. (1988). A review of the noxious plant Lantana camara. Toxicon 26: 975-987.

Editors

Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.

Acknowledgments

This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET Regional Coordinator: eafrinet@africaonline.co.ke