Invasive Species Spotlight: Toxic Invaders
Some of Hillsborough County's invasive plants are dangerous not only to native ecosystems, but also to people and pets!
Balsam Apple, Momordica charantia
Many of us can identify at least one invasive plant; you may have seen some on a hike at a Hillsborough County nature preserve or conservation park, and most Hillsborough County residents probably have at least one species of invasive plant growing in their neighborhood. Our roadsides are lined with Brazilian pepper, cogon grass, and camphor trees, and many other invasive plants have flourished and spread throughout the state. These species are capable not only of growing and reproducing on their own in the wild, but also of expanding their range and threatening or altering native plant communities. Invasive plants in Florida cover hundreds of thousands of acres, threaten many of our imperiled plant species, and cause negative changes to Florida’s ecosystems. Some invasive plants, however, can actually cause damage to humans and livestock as well.
There are many inedible or even poisonous plant species in Florida, but today we’ll spotlight just three of the most common invasive plants found in Hillsborough County: rosary pea, balsam apple (also known as bitter melon or balsam pear vine), and tropical soda apple. These plants are actually poisonous to livestock and humans when their fruits and seeds are eaten, and they can be especially tempting to children due to the coloring and shape of their seeds and fruits. All three of these species are often seen in gardens and along roadsides or trails. Below, we’ll show you how to identify these plants so that you can keep an eye out for them on your property and in your neighborhood.
Rosary Pea, Abrus precatorius
Rosary pea is a slender, delicate-looking invasive vine with pinnate- leafleted leaves. It grows up trellises, bushes, trees and houses. It can grow very quickly and can cover and shade out bushes and trees if left alone. Rosary pea has deep, well-seated roots and is extremely difficult to pull completely out of the ground- homeowners may need several applications of herbicide to kill it completely, or to pull it multiple times as it re-grows. Removing this plant is worth the trouble; the seeds contain a potent toxin called abrin and one seed can be fatal to an adult or a child if it’s chewed and swallowed. Unfortunately, the pretty, bright red and black seeds are quite tempting to children.
Balsam apple is an extremely weedy and fast-growing invasive vine with palmate leaves that is often found growing in disturbed areas, but can also colonize gardens and lawns. It grows easily along the ground and over trees and fences. It has a slightly furry stem and a faint unpleasant smell, and can be difficult to get rid of because the vine breaks very easily when pulled. The seeds are extremely viable, so when removing this vine from your property, make sure to remove the fruits and seeds and not let them fall to the ground. When the bright-orange fruits or large, red, shiny seeds are ingested, they can cause vomiting, diarrhea and a host of other problems in both humans and pets.
Tropical Soda Apple, Solanum viarum
Tropical soda apple is more often seen in pastures and open areas than in gardens, but it can easily colonize suburban lawns, especially if you live close to a natural area or a pasture. It’s a free-standing plant with large, furry leaves and huge, sharp, spiky thorns. These thorns make it difficult to remove- you’ll need very thick leather gloves and plenty of caution, as some larger thorns can penetrate gloves and even boots. The round, green, shiny fruits resemble a tiny watermelon or a green tomato and can be very attractive to children. Tropical soda apple is in the nightshade family and its fruit contains solasadine, a chemical that’s poisonous to humans and some animals when ingested.
