Native to South and Central America, Miconia thrives in wet areas and in deep shade. Miconia was imported to Hawaii Island as a botanical specimen in 1961 by a prominent Hilo resident. According to legend, the first Miconia plants died, and the pot was discarded under a dark greenhouse bench. Sometime later new plants appeared in the pot, which was then shared among plant enthusiasts on the East side of the Big Island. Dr. Forsberg, a botanist specializing in the Pacific, warned authorities in 1971 about the destructive nature of Miconia “It is the one plant that could really destroy native the Hawaiian forests”, he said. An expanding population around Onomea was noticed in the 1980’s, unfortunately, volunteer efforts for mechanical removal were not sufficient for eradication. Earnest attempts to eradicate this pest have been ongoing since the mid 90’s. As one of the most studied and documented invasive plants, it’s ironic that reports of Miconia’s naturalization and literature documenting its invasion are absent from natural literature until the 1990’s. Today, Miconia is listed as a state noxious weed and as one of Hawaii’s Most Invasive Horticultural Plants. Studies have shown that 1 tree can produce 3 to 9 million viable seeds in 1 year, remaining viable for (at least) 19 years in the soil. The build-up “seed deposits” in the seed bank makes mechanical and chemical eradication almost impossible.
- Able to grow up to 49′ with broad distinct leaves and shallow roots
- Large oval-shaped leaves, green on top, purple underneath, with three main midribs running from stem to leaf-tip, each leaf can get up to 3′ wide
- Flowers are small in size, white to light pink in color, grow on a stalk in clusters
- Fruits are plentiful, dark purple, sweet and attractive to birds. Each 1/2 cm in diameter fruit is packed with about 120-230 seeds
- Plant begin producing fruit as early as 4 years, one plant can produce up to three to nine million seeds each year
- Forms thick stands, shades out native plants and completely takes over moist and wet forests creating a monotypic forest
- Forms an “umbrella” over the watershed, reducing the amount of rainwater that seeps into the watershed
- Shallow root systems promote erosion, degrading the quality of surface water and increasing sedimentation of nearshore reefs
- Sand-grained sized seeds easily spread by birds and other animals when they eat the fruit. Seeds also spread by people when contaminated dirt or mud sticks to shoes, clothing, equipment, or vehicles
- Introduced to Tahiti in 1937 and has since overwhelmed two-thirds of Tahiti’s forests, and is directly responsible for threatening 25% of their native forest species with extinction
- Self Fertilizing- One sand sized seed, eaten by a bird and excreted far away, can create a new monotypic forest
Hawai’i Island: Populations occur on the East side in lower elevations with ample rain. Efforts to prevent miconia populations from spreading are underway my BIISC.
Maui : Infestations now occur in the forests near Hana, Nahiku, Keanae and Huelo. Efforts to prevent miconia populations from spreading are underway my MISC.
Oahu : Several locations in the Ko‘olau mountain range are being controlled by OISC with a goal of eradication.
Kauai : Small populations in Wailua River State Park, Wailua Homesteads, and the Wailua Game Management Area are being controlled by KISC with a goal of eradication.