The pretty plant is a serious threat to Hawaii's natural areas. In Tahiti, Miconia have squeezed out native plants in an estimated two-thirds of the island's forests. A mature Miconia can reach 45 feet, blocking sun and eventually killing native species. A mature Miconia also produces hundreds of tiny fruits eaten by birds such as cardinals, finches and white eyes, Hobdy said. The small, sweet fruits contain hundreds of seeds that are scattered in droppings.
Herbicides are a stopgap while researchers look for a solution.
Hobdy said the plants take about five years to mature. If the mature plants can be killed, that at least will stop the spread of more seeds, he said. But the key will be finding what controls Miconia in its native habitats in South and Central America. Shishido said a work crew tries to spend at least one day a week knocking down East Hawaii Miconia patches. On Oahu, Sierra Club volunteers help state forestry officials uproot plants.