Identification: This sprawling ornamental shrub grows from 9-15 ft tall with arching stems. Leaves grow in an opposite orientation and are dark green on top and woolly white underneath. Small orange flowers (1/10" long) form in cylindrical clusters. Small fruits start pink-white and mature purple. Smokebush's hairy stems gives the shrub an overall frosted white look.
Impacts: This plant is considered a high risk according to the Hawaii Pacific Weed Risk Assessment. It is recognized as invasive in Florida, Australia, South Africa, and the Caribbean. Its dense growth smothers other plants, overgrows trees, and destroys habitat.
Dispersal Mechanism: Seeds are dispersed by birds and animals who are attracted to its fruit. Can spread from stem cuttings and dumped garden clippings.
Origin, Distribution, and Habitat: Native to Madagascar, this plant has been introduced to worldwide tropical regions. On the islands of Maui and Kauai these shrubs goes wild in low to mid-elevation gulches, streambeds, and open range. It has been found in a few locations around Volcano on the Big Island where BIISC is removing it.
Cultivation: Smokebush is sometimes grown as a privacy hedge and a butterfly attractant. The Kauai Landscaping Industry Council put this plant on its "Don't Sell" list as part of Voluntary Codes of Conduct. If you see this plant anywhere on Big Island, please report it.
Dog tail (Buddleja asiatica) flowers going to seed.
Other Buddleia species:
Other Buddleia species are cultivated in Hawaii. Dog tail (Buddleja asiatica) has been planted and become naturalized on Oahu, Molokai, Lanai, Maui, and Hawaii. Butterfly bush (Buddleja asiaticaa) is also planted in Hawaiian gardens where it will sometimes jump the fence. Both plants are very similar looking to smoke bush but have white or purple flowers.
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.