A purple leaf underside is the most easily recognizable feature, along with a velvety or shiny, dark green color and three bold leaf veins. The hundreds of small, pink fruits each contain 150 seeds, and are attractive to fruit-eating birds, which spread the seeds great distances.
Introduced to a botanical garden on Tahiti in 1937, Miconia quickly escaped by bird carried seeds. Over 60% of the island is heavily invaded with dark groves of Miconia trees, replacing the native forest and its wildlife. French Polynesia scientists estimate 1/4 of indigenous Tahitian species are threatened with extinction. Miconia can do the same in Hawaii, since habitats are similar.
Miconia calvescens, in the Melastome family, has an attractive leaf which lures people to transplant it and unknowingly start infestations. It has superficial roots that allow excessive soil erosion.
The most frightening aspect of the tropical American tree Miconia (which left its natural control agents at home) is its ability to thrive in shade as well as sunlight. Seedlings spring up even in deep shade, providing excessive competition in gardens and for native plants, especially ferns in natural areas. Hawaii noxious plant experts urge that it be eradicated by everyone.
REPORT NEW LOCATIONS OF MICONIA TO: Hawaii State Department of Agriculture, Pest Control Branch, Weed Control Specialists: Oahu 973-9538; 1428 S. King St., Honolulu, Hi 96814; Maui 871-5656; Hilo 933-4447; Kona 323-2608; Molokai 567-6150; Kauai 241-3413; or National Park Service Scientists: Haleakala 572-4472; Volcano 967-8211
To protect agriculture and the unique ecosystems of Hawaii, it is imperative to recognize threats before they become out of control. People from Tahiti have warned state agriculture officials in Hawaii of the seriousness of this pest to prevent the spread of Miconia. To control it in French Polynesia, a new quarantine rule is attempting to limit the spread of this "purple botanic plague."
Citizens can perform a valuable service to the native flora and fauna in the ecosystems of Hawaii by increasing awareness of the threat of non-native plants and animals. Most importations are made with good intentions, not realizing the possible dire consequences. You can help slow the spread of this weed. It is important to alert the general public, nurseries, and botanical gardens on the dangers posed by this seemingly innocent, ornamental plant. It threatens to be a bigger pest than Koster's Curse (Clidemia hirta), another aggressive member of the prolific and infamous melastome family.
Please help by reporting new locations so that officials may map all sites and devise an effective control strategy. Phone or write the nearest contact listed on the reverse side with information on the size, quantity and locations of Miconia. Land owners are urged to cooperate by pulling up or cutting down and killing Miconia. Efforts to contain patches should continue until a long term solution, such as biological control by natural enemies, is developed.
by Timothy Hurley, Staff Writer
Reprinted from Maui News, May 1991
Always wary of threats to native species, the scientists at Haleakala National Park have launched a campaign against another island newcomer that threatens to overrun native forests.
This time the focus is on an aggressive invader named Miconia calvescens, a tree species in the melastome family from South and Central America.
Scientists say miconia has shown what it can do to destroy native forests on other tropical islands, and its aggressive characteristics already are apparent from their brief experience with it here.
The tree has been found in at least seven locations on Maui, and scientists say if they can get on top of it now, the problem might be quashed. But they're really not sure of the scope of this problem.
Lloyd Loope, Haleakala research scientist, said he is hopeful the species can be kept in check on Maui by uprooting what they've found by hand.
That's not the case on the Big Island, he said, where miconia has gained a foothold in the native forests and where scientists are trying to figure out some sort of biological control.
An attractive plant with huge, 2-foot long dark green leaves with purple undersides, miconia was introduced to Hawaii within the decade through the horticulture industry on at least three islands; Hawaii, Oahu and Maui, the scientist said.
All species are thought to be held in check in their native habitat by natural agents that have evolved to exploit them. Release from these natural enemies allows some species to thrive spectacularly when introduced to a new area where its enemies are absent. This is the case with miconia.
After only a few years of growth, the miconia tree can produce hundreds of thousands of seeds a year.
Scientists say miconia has infiltrated the forests of Tahiti and Moorea over the past two decades. It also has taken over parts of Sri Lanka.
"It can be a major, major problem here," cautioned Clifford Smith, University of Hawaii botany professor. "It could really be a disaster for the wet native forests."
Haleakala scientists learned about the threat of miconia here recently when one of the park's employees noticed a single tree growing in Alii Gardens near Hana.
The owner agreed to remove the plant.
Since that time, the scientists have learned the weed is spreading on Maui at a disturbing pace, Loope said.
Loope said the miconia is believed to have first reached windward eastern Maul in the early 1980s, with the original plants having already grown more than 30 feet tall and producing abundant seedlings.
One particularly large stand, with dozens of trees, is found in Helani Gardens in Hana.
"When I saw it at Helani, it was the first time I said, 'Wow, this is a problem,' " Loope recalled.
Helani owner Howard Cooper said he discovered the plant in his garden about five years ago when it appeared with some other potted plants he had bought. "It's a beautiful plant but it's a pest," he said.