According to the Florida Exotic Pest Plant Council, the spread of invasive exotics is second only to direct habitat destruction in creating adverse effects on Florida’s natural habitats.
Invasive plants are exotic plants that become widespread enough to pose a threat to the local ecosystem. Imported from elsewhere, they take resources away from native plants. In a new environment without natural pests, diseases, or ~predators, exotic plants can proliferate rapidly. When they out-compete native plants, creatures that depended on those plants for food and shelter fair poorly as well. Only some exotics become invasive, but the ones that do can threaten thousands of miles of habitat and hundreds of different species.
Residents at a neighborhood meeting were asked to nominate, then pick their top three invasive plants of concern. (Note: Charlie’s thin grass isn’t a real name, but rather a description of a unknown grass found on a resident’s property.) The results were:
![[graph of disliked invasive plants]](/images/dislikedinvasives-sm)
Air Potato
![[an air potato]](/images/potatovine)
Air potato (Dioscorea bulbifera) was our invasive of greatest concern. Air potato is a member of the yam family (Dioscoreaceae) and is a vine typified by large leaves and potato-like aerial tubers growing out of the stems. Stems are herbaceous (not woody) and round, leaves are cordate (heart-shaped) and radiate from a single point. The tubers produce new plants.
Dioscorea was introduced into Florida in 1905 for purposes of decoration and food (but caution! uncultivated varieties may be poisonous!).
Brazilian Pepper
Brazilian pepper-tree (Schinus terebinthifolius) is a very aggressive invasive plant. It is successful in both aquatic and terrestrial habitats. Originally from South America, it was introduced to Florida as an ornamental plant in the 1800s. Related to poison ivy, the plant causes a rash for some people, so handle with gloves.
Virginia Creeper
Virginia creeper (Parthenocissus quinquefolia) is actually native. It is a member of the grape family, and the dark fruits are eaten by dozens of birds.
Melaleuca
Melaleuca (Melaleuca quinquenervia) was imported from Australia in the 1900s to suck up water and speed development of swampland. Melaleuca was overly successful, and has spread throughout Florida, destroying native habitat. Hundreds of thousands of acres of the Everglades have been overrun by thick strands of melaleuca. It is so pervasive and damaging that it is listed on the Federal Noxious Weed list, and it is an especially difficult plant to control. Burning the trees causes them to release seeds. The most successful method of controlling the trees so far has been importing insects that are desctructive to the Melaleuca.
Springeri fern
Springeri (Asparagus densiflorus) is also known as Asparagus Fern. It is a perennial herb, growing 2 feet in height, with stiff stems and flat, bright-green seeds. It was brought over from South Africa for use as potted plants and ground cover, and now displaces native underbrush.
Poison Ivy
Poison ivy (Toxicodendron radicans) is actually native to Florida. Urushiol oil on the plant leaves causes blistering, itching rashes in most people, and so it is considered a pest.
Australian Pine
Australian pine (Casuarina equisetifolia) was introduced from Australia in the 1800s for lumber and use as windbreaks. Its rapid growth and great height allow it to block the sunlight needed by other plants. It is very successful in sandy soil, often crowding out native plants needed for erosion control of beaches. Australian pine increases the acidity of the soil, and seeds all year.
Australian pine “needles” are jointed branches arranged in whorls, and look banded from a slight distance because of the joints.
Rosary Pea
Rosary pea (Abrus Precatorius) is a vine with extremely poisonous seeds. Eating a single seed can leave to death, and the shiney, bright red berries are very attractive. The plant has a woody, somewhat hairy vine with clusters of pink or lavender flowers. Native to India, it has spread to the Virgin Islands and Southern US, and is a category 1 invasive. Rosary pea is especially common in disturbed areas.