Hawaii Declares War on the ‘Green Cancer’ Plant

“Wanted, dead or alive” posters have been issued, posses of volunteers have been formed, and a statewide alarm has been sounded.

The sheriff isn’t looking for bank robbers or rustlers.

The culprit is a plant sometimes called a “green cancer.”

In most gardens, the attractive miconia calvescens plant would be a star attraction with its huge leaves. They are deep green on the top and purple on the bottom and have an artistic vein pattern.

Left unchecked in the tropical wilds of Hawaii, however, in a few decades the hardy plant would wipe out and replace the native forests, destroy the ground cover that creates the vital watershed and eliminate many of the island’s unique animals, officials say.

“Its presence is a natural disaster waiting to happen,” said Gov. Ben Cayetano, who recently announced a coordinated effort to eradicate the plant.

Introduced as three small garden plantings in 1937, miconia now covers 70% of the forests in Tahiti, where it is known as the “green cancer.”

“The good news is that, unlike Tahiti, we have discovered the miconia problem in time and are acting to remove this weed before it’s too late,” Cayetano said. “Our goal is to reach every household in the state to enlist everyone’s help in locating this plant and preventing its spread.”

Well, that might be easier said than done.

Already, the plant introduced in the state as an ornamental in the 1960s has been discovered in 36 locations in about 10,000 acres of native forests. The biggest infestation is on the island of Hawaii, with about 1,000 acres on Maui and small pockets on Oahu and Kauai.

On Maui, Oahu and Kauai, where the infestations are relatively small, the eradication could be accomplished within a few years, but on the island of Hawaii it could take much longer, said Mike Wilson, director of the Department of Land and Natural Resources.

The fast-growing plant reaches maturity in five years. It produces a small fruit that contains hundreds of tiny seeds that are spread by birds eating the fruit, Wilson said.

The plant evolved in competition with equally aggressive plants in the jungles of Brazil. It grows in thickets reaching 50 feet high with the 3-foot-long, heart-shaped leaves creating a dense canopy that blocks out sunlight to the delicate native plants below.

The shading kills the native plants on which many endangered native bird species depend as well as the ground cover that traps the water on which Hawaii’s human population depends.

“The erosion caused by this weed could also damage our beaches and swimming areas, our No. 1 visitor attraction,” Wilson said.

In Hawaii, miconia has no natural enemies and scientists have not yet found a successful biological agent to combat it.

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Workers and volunteers began the assault earlier this month in the forests on Maui and the island of Hawaii, called the Big Island, pulling out and sawing or chopping up thousands of the plants.

If the plant is young, it simply can be uprooted and left to die. But if the plant is mature and is seeding, care must be taken because the tiny seeds can be picked up by muddy boots and equipment and spread to other parts of the forest.

Meanwhile, teams of volunteers fanned out through suburban neighborhoods abutting the forests to pass out the wanted posters and advise residents to destroy any plants they find on their property.

The culprit is at large, but the sheriff and his deputies are hot on the trail.