Miconia

miconiaMiconia (Miconia calvescens)

(Melastomataceae)

Considered very invasive and is on the Hawaii State Noxious Weed List. The Division of Forestry and Wildlife of the Hawaii Department of Land and Natural Resources has designated this species as one of Hawaii’s Most Invasive Horticultural Plants.

miconia2Description:

  • Large tree grows up to 50 feet tall
  • Large oval-shaped leaves, green on top, purple underneath, with three main midribs running from stem to leaf-tip
  • Native to South and Central America, introduced to Hawaii as a garden plant in 1961 and spread around by plant enthusiasts.

Harm:

  • Forms thick stands, shades out native plants and completely takes over moist and wet forests
  • Forms an “umbrella” over the watershed, potentially reducing the amount of rainwater that seeps into the watershed.
  • Shallow root systems promote erosion
  • Can grow from seed to mature seeding tree in four years. A mature tree can produce about 3 million seeds several times per year. Seeds can remain viable for 10 or more years before sprouting
  • 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.

In Hawaii:

  • Kauai: One population known, in the Wailua State Park and Homesteads area. KISC works with partners to survey for and control all known miconia on Kauai. Land owners and tenants can allow KISC to survey their property and eradicate miconia.
  • Oahu: Originally introduced and traded amongst botanical gardens in the early 1960′s, miconia has since spread into several locations in the Koolau range. The potential population boundary extends to 9,500 acres (including areas considered “seed banks”). If left uncontrolled, miconia could infest up to 121,300 acres on Oahu. OISC is working to survey all population boundaries to completely eradicate it from Oahu.
  • Maui: Introduced to Maui in the early 1970s at a private nursery and botanical gardens near Hana. Infestations now occur in the forests near Hana, Nahiku, Keanae and Huelo. Today, approximately 37,000 acres throughout East Maui, could potentially contain miconia. Not known from West Maui.
  • Molokai: Miconia is not known to be present at this time. Seeds could arrive in soil on hiker’s or hunter’s shoes or gear, or on native tree fern logs imported from the Big Island. MoMISC educates community members to aid in early detection.
  • Lanai: None known.
  • Kahoolawe: None known.
  • Big Island: Large infestations on the windward side, with a smaller population on the leeward side. BIISC works to control populations on the windward side; community groups and private landowners also assist in some locations.

For more information, see: