Attack of the Alien Invaders, National Geographic Magazine: Aggressive Melaleuca Begins With A Tiny Seed

Close up of hand holding branch of leaves with small brown seed pod.

The Melaleuca tree is considered the most prominent of 60 non-native plant species invading south Florida. Each seedpod contains up to 200 seeds, which are released into the environment when the tree is subjected to stress factors such as fire, herbicides, or manual cutting. A mature tree can produce up to 20 million seeds per year, making this tree a land manager’s nightmare.

The invasive Melaleuca tree (Melaleuca quinquenervia) took over 500,000 acres of wetlands before restoration efforts were initiated near Lake Okeechobee in Florida. Everglades National Park and the South Florida Water Management District have spent 25 million dollars  a ten-year effort to eradicate the plant.

An exotic import from Australia, the tree was originally brought to Florida in the early 1900s as a landscaping ornamental and to help dry out wetlands. A mature Melaleuca forms a dense monoculture, choking out other plants in the Everglades. It uses up to seven times as much water as a native tree.

Buy This Image