Plants of Texas Rangelands

Virtual Herbarium

Largeleaf Lantana

Lantana camara L.

Verbenaceae

Description

Lantana is a branching shrub reaching up to 6 feet or 1.8 m tall. It has spreading, ascending branches usually having a few small prickles. New growth has square and haired stems. The branches are opposite and arise from leaf axils. Lantana’s oval leaves are rough, opposite, simple, and have serrated edges. The many-flowered heads are on long stems usually arising from the axils of the leaves and are often bicolored. Lantana flowers are small, stalked, and form clusters that measure about 1.5 inches or 4 cm across. There are pink and white, yellow and orange, and orange and red varieties. Some of the newer ornamental varieties have single-colored flowers. The clustered, round fruits are about 0.2 inches in diameter. Each fruit is a two-seeded drupe that starts as a green color, changes to a deep purple, and matures to a shiny, black color when ripe. Lantanas are effective in attracting butterflies. 

Habitat

Lantana camara is native to South Texas, Tropical America, and was widely planted as an ornamental as the state was settled. It is still a common shrub and has escaped in many areas. Lantana thrives in well-drained, sunny locations and will grow in sandy soils along the Gulf Coast where other plants are damaged by the salt. It often grows under brush and along fences, where birds apparently deposited the seeds. 

Toxic Agent

Triterpenes, lantadene A and lantadene B, from Largeleaf Lantana, are responsible for the toxicity of the plant and are present in all plant parts. These toxins affect cattle, sheep, goats, horses, dogs, and humans. The degree of liver injury produced by the plant directly reflects the amount of Lantana ingested. Low levels give slight liver damage, producing increases in liver enzymes present in the serum. Higher amounts result in cholestasis and microscopic changes in the liver. Very high doses result in widespread liver necrosis or death of liver cells and can cause death within two days. Just 5 grams of dried leaves could cause death for sheep and cattle. Horses are less sensitive, and goats are susceptible to the toxins but are less likely to consume the plant. 

Signs of Livestock Ingestion

Although horses usually do not exhibit signs of photosensitization, the other clinical signs are similar in all species and include: Loss of Appetite, Constipation, Sluggishness; Weakness; Bloody diarrhea; Jaundice (yellow whites of the eyes, yellow skin; yellow fat and liver after death); Secondary photosensitization. 

Management Strategies

Livestock should not be forced to consume Lantana. Good range management with adequate palatable forage will prevent excess consumption. Allow poisoned animals to remain in the shade and give them sun-bleached hay, feed, and water to recuperate. 

Images

Largeleaf lantana: Whole Plant
Largeleaf lantana: Flower
Largeleaf lantana: Fruit
Largeleaf lantana: Leaf

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