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The Lantana conundrum: How to choose a non-invasive species for your garden

Lantana depressa var depressa, pineland shrub verbena. Note the inwardly curled leaves.
Lantana depressa var depressa, pineland shrub verbena. Note the inwardly curled leaves. Fairchild Tropical Botanic Garden

Lantana is touted as a wonderful butterfly magnet, and it is. But there are cautions to be aware of when buying it.

Lantana camara is the all-too-common species you are likely to encounter. Though many Lantana species are shrubby and herbaceous, this one gets fairly woody stems, which are flattened and square-ish. It can spread by rooting where branches dip down to touch the soil. I have found that it quickly fills in an area, pushes out other plants, then tends to get leggy, woody, prickly and unattractive. The flowers are small, in clusters, and can be orange, red, white, and pink. The mature fruit is blackish purple and pearl-sized.

Many plants are aggressive, but Lantana camara (also called Lantana strigocamara) is a Category 1 invasive plant pest, meaning it’s invading native areas, displacing native plants, and hybridizing with related native plants — and it’s been here and in many parts of the world a long time. It’s a perfect storm: The plant thrives in disturbed areas, nutrient-poor soil, is toxic to herbivores, produces chemicals to deter other plants from growing too close to it, entices birds to spread its seed, and will often re-grow despite attempts at removal.

Even worse, L. camara is known to hybridize with the Florida native plant Lantana depressa var. depressa, called pineland or rockland shrub verbena, which means the true native can be eliminated through hybridization. This begs bigger questions like what it even means to be native, and even what constitutes a species. For matters of conservation however, it’s best to discourage the hybridization.

Flowers are often a reliable way to identify plants, but unfortunately not in the hybrid’s case. Lantana camara flowers are pretty variable in color, with yellow, pink, purple, lavender and orangey-red possible. While the native pineland shrub verbena (L. depressa var. depressa) always produces bright yellow flowers, if it hybridizes with L. camara, the flowers may be the same yellow and the plant might pass for the native. Interestingly, the pineland shrub verbena is endemic to Miami-Dade County pinelands. Nowhere else on Earth does it occur naturally.

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The rare hammock shrub verbena (Lantana canescens), a species straddling two ecosystems. KENNETH SETZER Fairchild Tropical Botanic Garden

Brian Harding, a conservation horticulturist at Fairchild, has propagated native Lantana. He says there are certainly hybrids out in natural areas, but a couple of identifying clues are in the leaves: native pineland shrub verbena’s foliage is tapered as it meets the stem, or petiole, while Lantana camara’s leaves flare out towards the base. The native’s leaves also tend to roll inwards at the leaf margins, while camara’s are flat.

To make matters more confusing, there are also a number of cultivars (a cultivated, human-made variety) with Lantana camara parentage available that offer yellow flowers and resemble the native Lantana, though thankfully these are thought to be sterile.

Our conservation team also cultivates the very rare hammock shrub verbena (Lantana canescens), a resident of the ecotone, or transition, between hardwood hammocks and pine rocklands, for growing at Fairchild and for restoration in natural areas.

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Lantana involucrata, button sage. KENNETH SETZER Fairchild Tropical Botanic Garden

A slightly more common native is Lantana involucrata, button sage, or wild sage. It’s got much rounder leaves especially near the petiole than shrub verbena, but produces small bunches of white flowers with yellow centers followed by cheerful lavender-purple fruit. It attracts butterflies, skippers, beetles, bees and birds, a wildlife-supporting magnet.

If you are looking to plant native, don’t be fooled by the similar-looking cultivars. You can see these lantanas for yourself in Fairchild’s South Florida butterfly garden and pineland exhibit. Our Members’ Day Plant Sale on Oct. 6 will offer Lantana involucrata and Lantana depressa var. depressa plants, in addition to dozens of other plants both exotic and native, with some only recently collected overseas.

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