6 Invasive Non-Native Plants in Florida

Invasive plants can be such a problem for places like Florida. What are some of the most common non-native plants?

Because of Florida’s welcoming climate, the Sunshine State’s ecology is tormented by hundreds of invasive plant species, which can pose major difficulties for native plants and wildlife.

Here are ten of Florida’s most troublesome invasive plants.

What are Non-Native Plants?

Non-native plants are those plants that have been intentionally or incidentally brought to a region outside of their natural range.

Plants from different nations, regions, or continents are commonly referred to as non-native. 

Around 1,400 of Florida’s plants are not native to the state.

The Problems with Invasive Plants

On millions of acres of southeastern forests, invasive plants have a negative impact on forest health, production, access and usage, and forest management expenses, as well as limiting species diversification. 

Native flora and fauna are displaced, and natural processes such as fire regimes and hydrology are influenced.

Invasive aquatic plants are particularly problematic in Florida, where they may obstruct navigation and flood management, impair recreational water usage, drastically lower dissolved oxygen levels resulting in fish mortality, as well as provide mosquito breeding grounds.

White yellow flower lonicera japonica

1. Skunk Vine

Skunkvine is a twining, invasive coffee vine of the Rubiaceae family. The common name refers to the plant’s sulfur-containing leaves, which emit a horrible stink. Its scientific name, Paederia foetida, translates as “bad-smelling odor.”

It was introduced to Florida as a sustainable fiber cultivar from Asia’s tropical regions in the late 1800s.

This invasive plant in Florida is categorized as a noxious weed, making it illegal to sell, import, cultivate, breed, export, or transport it.

Skunkvine freezes to the ground in the northern parts of Florida every winter and emerges from the roots in the spring, however, it is perennial in the central and southern parts of the state.

The leaves are opposite (sometimes in three whorls), oblong-shaped to lance-shaped, and have lobed bases. They have toothless leaf margins and grow 1–4.3 inches long with prominent stipules (appendages at leaf bases). Leaf surfaces may be hairy or non-hairy.

The small blossoms are pale pink or mauve in hue and clustered in broad or long, “leafy,” curving clusters. Petals fuse to form a tube (corolla) with five expanding lobes (the corolla is dense and hairy).

It forms up to 35-foot-long stems that extend to the ground, over trees and shrubs, and even over man-made structures such as fences and light poles.

Its dense growth has the potential to injure and kill natural flora. Climbing vines may fully engulf and swallow trees and vegetation. 

The weight of the vine mass creeping over plants may topple limbs or trees. Their crawling vines may form a dense understory layer that suffocates many shrubberies and other nearby plants. 

As a consequence of these impacts, plant diversity is diminished, and forest succession is changed.

white and red flowers of a skunk vine

2. Melaleuca tree

Melaleuca was introduced to Florida from Australia around 1900 and quickly became popular as a decorative tree as well as a soil stabilizing agent on levees and spoil islands.

It was also grown in 1967 to drain away the Everglades in order to reduce mosquito infestations and allow for development. Later it was forecasted that it had occupied 488,000 acres in South Florida by 1993.

Melaleuca has been labeled as a noxious weed by federal and state agencies, making it a criminal offense to sell, import, produce, breed, export, or transport it.

Melaleuca is a huge evergreen tree that grows to be 65 feet tall and has a brownish white, multi-layered crinkly bark.

It produces white, bottlebrush-like flowers. Seeds are enclosed in woody capsules that form clusters on stalks.

Melaleuca generates massive amounts of seeds that are distributed by wind and grow into little trees that mature into practically insurmountable monocultures.

It can grow in both land and marine habitats and has been especially destructive in the Everglades. It has altered water flow, displaced endemic plant species, and reduced habitat and food sources for wildlife.

They have the ability to flower five times every year. Any tree injury that reduces water supply to the stems bearing seed capsules, such as fires, freezes, and management tactics, will result in seed release. 

Seeds can live for up to ten years, and one tree can carry up to 20 million seeds each year.

Melaleuca forests pose a significant fire risk to nearby built areas due to the oils found in the leaves, which ignite hot crown fires.

A blooming herd of white flowers tea tree

3. Japanese honeysuckle

Lonicera japonica (Japanese honeysuckle) is a perennial honeysuckle vine that grows via seeds, underground rhizomes, and above-ground runners. It can be observed trailing or ascending to a height of more than 80 feet (24 meters).

It has opposite, oval leaves that are 4-8 cm long and semi-evergreen to evergreen. On older stems, the bark is brownish and peels in huge strips.

The sweet-smelling flowers are formed in sets and have two pairs of lips. Five tightly triangular sepals are linked at the base. The hollow cylindrical, five-lobed bilabiate corolla is either white or creamy in color, becoming yellowish upon maturity. The corolla gives off the five stamens.

The little glossy spherical fruits turn from green to black as they ripen. Each fruit contains 2-3 oval brown to black seeds.

It is notorious for swiftly colonizing open regions. Birds ingest fruits and disseminate seeds, resulting in a vast seed bank and broad ecological adaptation.

By out-competing native plants for light, water, territory, and nutrients, Lonicera japonica is able to replace native species. They spread quickly and send forth runners that anchor and flourish in any location.

Honeysuckle vines will fasten themselves around everything in nature, eventually swallowing small plant life. The weight of the foliage may force trees and plants to topple.

Dense vegetation inhibits many native species from sprouting and developing, ultimately reducing understory shrub and tree regeneration. 

Honeysuckle promotes the spread of a wide range of invasive species, diminishing the natural diversity of forests and ecological spaces.

There are other possibilities for people looking for a nearly equivalent vining plant. Coral honeysuckle, sometimes known as trumpet honeysuckle, is a natural shrub that differs from the invasive honeysuckle by generating orange or red blooms instead of white blooms

Star jasmine has scented blossoms as well, which makes it a good alternative. Other substitutes include trumpet creeper, passion vine, cross vine, and millettia.

Yellow lonicera japonica flowers in the garden

4. Chinese Tallow Tree

Chinese tallow is widely cultivated in China for seed oil. 

The seeds produce two forms of fat: a solid fat from the outer layer and a drying oil from the kernel. The oil was used as an equipment lubricant, while the fat was used to make soap and candles.

This tree’s close-grained white wood is used by the Chinese for sculptures and furniture.

This is also a spectacular display in the fall, when its leaves turn a rich scarlet, especially in Florida, where exceptional autumn leaf color is rare.

In the 1700s, the Chinese tallow was brought to the United States primarily as a decorative tree. However, naturalization has now occurred in half of Florida’s counties.

It’s a small to medium-sized tree that can reach 20 feet in height, with some types reaching 40-50 feet. 

It blooms from January to February and has seeds that ripen in November. The species, which is monoecious, is pollinated by insects and bees (individual blooms are either male or female, although both sexes may be found on the same plant).

The fruit is a three-lobed (0.5 inches) capsule with seeds encased in a white waxy coating called vegetable tallow. The fruit ripens from August to November.

It has alternating oriented leaves on twigs and branches freely. With widely ovoid leaf blades and curved bases, the leaves have acuminate points and whole edges.

Larger specimens can generate up to 100,000 seeds, which are consumed and carried by birds, allowing tallow to spread. Cut stumps and roots are frequently regrown.

Native species are pushed out once the Chinese tallow has established itself. The leaves and berries harm cattle and cause nausea and vomiting in humans.

When the plant is damaged, it produces a toxic, milky sap.

Blossoms of a chinese tallow tree

5. Crested Floating Heart 

The herbaceous, aquatic plant Nymphoides cristata has buoyant stems that grow from a submerged rootstock.

Thin tuberous roots sprout from the stem-leaf node.

The flowers can be pistillate (female) or hermaphroditic (both male and female), and they bloom from summer through autumn. They are white with membrane lines, petal lobes with a wrinkled crest (like a rooster’s comb) along the upper midvein, and membranous margins that are 0.3-0.9 inches wide.

Fruits are capsules with up to 20 seeds, each around 6 mm in size.

This water plant is native to Asia, but the aquatic plant nursery trade transported it to North America and sold it as “snowflake.” After evading cultivation in the United States, they were able to continue to grow and establish themselves in Florida water bodies.

They are most commonly found in shallow waters, anchored on sunken sedimentary rocks (less than 2 feet deep to approximately 10 feet deep). 

Tubers, daughter plants, roots, and fragmentation are all utilized to vegetatively reproduce the plant.

Once established, this species rapidly repopulates and spreads to new parts of the waterbody, generating mats of overhanging floating leaflets that overshadow underwater aquatic plants, thus blocking water circulation and reducing dissolved oxygen concentrations in the water column under the mat.

This plant has been classified as a “Category I” invasive species by the Florida Exotic Plant Pest Council, which means it has the potential to disturb native plant populations by eliminating native species and altering community dynamics or ecological processes.

Because of its rapid, aggressive development and vegetative spread, chemical treatment is regarded as the best strategy for controlling infestations and destroying new colonies.

Herbicides of many forms and combinations have been attempted, but none have proven to be long-lasting.

There are currently no identified insect herbivores that consume this species.

The weed-eating fish, the grass carp Ctenophryngodon idella, which is utilized for bioremediation of many water weeds, has also been shown to be unsuccessful in restricting the spreading of this plant.

little white crested flowers

6. Abrus precatorius

Abrus precatorius is a perennial climber that twines over trees, shrubs, and hedgerows. It lacks any specific anchoring organs.

The fruit (pod) is silky smooth and flat, elongated and truncate-shaped, with a pointed deflexed beak that is 3-5cm long and 1.2 cm wide. When the seedpod is opened to reveal the seeds, it spirals back up.

When the seed coat ruptures, the seeds release abrin, which is extremely poisonous. A single seed can lead to blindness or even fatality if ingested.

The plant has a widespread distribution area, overpowering local flora, and produces many seeds per pod, ranging from 3 to 8. 

It reproduces by scattering its crimson seeds, which are spread by both biotic and abiotic factors.

Rosary pea grows in uninterrupted pinelands and hammocks throughout central and southern Florida.

It has been listed as a Category I noxious weed in the US state of Florida due to its propensity to infiltrate and displace native plant populations.

It is also prone to infiltrating disturbed environments such as pastures and roadside ditches. Despite the lack of tendrils, rosary pea can grow over small trees and bushes.

It has a shallow taproot that makes removal difficult. Fire only gives temporary control.

It is a poisonous plant that contains Abrin, a toxalbumin that induces cell death by slowing protein synthesis. In India, the seeds are pulverized and ingested orally for suicide reasons, and the toxin has no known antidote.

Hand-pulling and elimination of complete plants, particularly the roots, is a possible alternative for minor invasions. Remove seed pods and seedlings if at all possible. Fire merely gives temporary control. 

Abrus precatorius climbing on the twines of plant
Alaine Connolly
Alaine has been working way too hard in horticulture since 1992, beautifying golf courses, resorts, and hotels. She is a part time landscape designer who works full time caring for a 28,000 square foot public garden. At home, she maintains her own 400 square feet plot. Alaine lives in northern Illinois - zone 5b.
More ArticlesDiseases and Pests