Hinilayan ginger, aka Kahili ginger, is already a widespread pest in Hawaii, but can be prevented from invading Molokai. This showy ginger plant grows in wet habitats from thick rhizomes to a height of 0.9-2.1 m (3-7 ft). The plant has lance-shaped leaves 20-45 cm (8-12 in) long and 10-15 cm (4-6 in) wide arranged in 2 rows along the length of the stem. One or more stalk, 16-30 cm (6-12 in) long, of flowerheads with strongly fragrant yellow flowers with elongated red stamens, are produced midsummer through fall. Seeds are bright red and orange within.
Impacts: Kahili ginger can rapidly grow into dense thickets displacing all other undergrowth in the rainforest and preventing the regeneration of all trees, plants, and fern in the rainforest. Once established it is difficult to remove. Kahili ginger has invaded and endagers the biodiversity of some of the most pristine native rainforests in Hawaii, such as Kipahulu Valley on Maui, Kokee on Kauai, and Kilauea on the island of Hawaii.
Dispersal Mechanism: Kahili ginger is native to eastern India and is a common garden planting in Hawaii. Fruit eating birds spread the seeds from the garden into the forest. Once established the ginger will spread vegetatively via densely growing rhizomes which sprout new stems. Even small root fragments will regrow. The island of Molokai is one of the few places in Hawaii where Kahili ginger is not established in natural areas (see map). If you see it anywhere on Molokai- let someone know!
White ginger (Hedychium coronarium)
Yellow ginger (Hedychium flavescens):
White and yellow ginger are common garden plants that are also found growing in the wild in Maui County. The flowers of white and yellow ginger are white and the flowerheads are much smaller than in kahili ginger.
Funding and support for this project was made possible by the Hawai'i Invasive Species Council, the USDA Forest Service State and Private Forestry assistance, and University of Hawai'i-Pacific Cooperative Studies Unit.