Fiddlewood (Citharexylum spinosum) An Alien Plant Report Prepared by: Forest Starr, Kim Martz and Lloyd Loope United States Geological Survey Biological Resources Division In cooperation with: American Water Works Association Research Foundation Maui County Board of Water Supply March, 1999
Fiddlewood (Citharexylum spinosum) What is fiddlewood? Why is it bad? Fiddlewood is a fast growing tree. It is distinguished by bright orange, deciduous leaves. Fiddlewood forms a dense canopy, and smothers vegetation. On O ahu, fiddlewood has proven its ability to invade native ecosystems in the Ko'olau range. On Maui, fiddlewood is currently found as a street tree in Kihei, Lahaina and upcountry where it spreading from initial plantings. What should you do if you see this plant in the wild? 1. Call the Hawaii Ecosystems at Risk (HEAR) project at 572-4418. 2. Pull out the tree, if possible. Otherwise, cut the tree near the root of the plant, and treat with an herbicide in accordance with label. 3. Please do not plant this plant. 4. For more information or additional copies of this flyer, call 572-4418, or websurf to www.hear.org. You can help keep Maui no ka oi. United States Geological Survey Maui County Biological Resources Division Board of Water Supply Fiddlewood (Citharexylum spinosum) 2 American Water Works Association Research Foundation
Fiddlewood (Citharexylum spinosum) Overview: Fiddlewood, which turns a beautiful orange in spring/summer is widely planted over much of the islands of O'ahu and Maui. It was previously thought to stay where it was planted, but has since been found spreading into adjacent land in Ha'iku, Kihei and Lahaina. Maui will never get rid of fiddlewood, but it can perhaps minimize potential future damage by not promoting fiddlewood in the landscape industry, taking fiddlewood out of the Maui county planting plan, and/or including it in a list of plants not to plant. Public involvement potential: People can keep their eyes open for fiddlewood, especially in natural areas, and alert USGS/BRD of new locations. Information can be shared with others including this report, flyers, and web pages. Please do not plant fiddlewood. Common Name: Fiddlewood. Latin Name: Citharexylum spinosum L. Synonyms: Citharexylum quadrandgulare, C. subserratum. Taxonomy: In the Verbenaceae (Verbena) family, Citharexylum is a genus of over 70 species from Bermuda, the West Indies, and southern United States through Mexico to South America. Fiddlewood's common name comes from the use of its wood to make stringed instruments by the people of the Caribbean (Turner and Wasson 1977). Fiddlewood's Latin name, Citharexylum spinosum, is derived from the Greek kithara (lyre or fiddle) and xylon (wood) (Wagner et al 1990). Description: Fast growing, evergreen, often multi-stemmed tree with a rounded crown that grows to about 40 ft (12 m). The glossy, oblong leaves are about 8 in (20 cm) long and turn from bright green in summer to copper and orange in winter and spring. Some leaves fall in spring, especially in colder climates. Long racemes of tiny, yellow-white, fragrant flowers appear in late summer to winter. Noxious Weed Acts: Citharexylum spinosum is not on the Hawai i state noxious weed list. Native Range: Native to the Caribbean (Turner and Wasson 1997). Range of Invasion: Global -- Not much is known about the global range of invasion of fiddlewood. Fiddlewood (Citharexylum spinosum) 3
State -- Fiddlewood can be found on the islands of O'ahu and Maui, where it is naturalized on both islands. It would not be surprising if fiddlewood plants existed on other islands, as it is a popular street tree. On O'ahu, fiddlewood Gerrish and Mueller- Dombois (1980) describe 2 infestations at Tantalus and Pupukea, where it grows in dry habitats generally below 500 m. There is a population at the bottom of the cliffs in Waimanalo in a very dry habitat (Smith 1998). Maui -- Fiddlewood is widely planted in Ha'iku, Kihei, Lahaina and Wailuku. Fiddlewood was found to be naturalized on west Maui in 1996 by Maui Pineapple Co. employees Hank Oppenheimer, Scott Meidell, and Randy Bartlett (Evenhuis 1997). It was found to be naturalized by the authors on east Maui in 1998 in the area of Ha'iku, especially 'Ohia gulch, and in Kihei. Fiddlewood can be found growing from near sea level in Lahaina to 3500 feet in Kula. The wetter areas have more potential for fiddlewood to reproduce, but fiddlewood is successfully spreading from a botanical garden in a very dry setting in Kihei to nearby Kealia Pond National Wildlife Refuge, and is also spreading near Lipoa in Kihei into the yards of nearby condominiums. Climate where invading: Fiddlewood can be found growing in a wide range of climatic conditions, from very dry to very wet habitats and from near sea level up to 3500 feet in elevation. Value to humans: Used as a street tree, fiddlewood is a popular ornamental, primarily in tropical and subtropical areas. The tree is stunning, and gives one the feeling of fall colors when its leaves turn orange and drop. Problems: Fiddlewood is a popular ornamental and has begun to produce seedlings in Hawai'i during the past twenty years or so. Ten years ago, it was though fiddlewood reproduced only in urban areas. However, Wagner et al. (1990) warned that fiddlewood may eventually become naturalized, and has recently been found to be established in the Ha'iku, Kihei, and Lahaina areas of Maui. Biology and Ecology: Fiddlewood is deciduous during the dry season, and it can be seen from a considerable distance when the leaves turn orange prior to fall. This is the best time to map fiddlewood. Physical control: If cut and not treated, fiddlewood will grow back. Chemical control: No trials have been done, but because fiddlewood is able to grow back after being cut to the ground, herbicides will likely play a role in any efforts to control fiddlewood. Biological control: It has not been evaluated for biological control (Smith 1998). Management recommendations: Fiddlewood, which turns a beautiful orange color, is widely planted over much of the islands of O'ahu and Maui. It was previously thought to stay where it was planted, but has since been found spreading into adjacent land in Fiddlewood (Citharexylum spinosum) 4
Ha'iku, Kihei, and Lahaina. Maui will never get rid of fiddlewood, but it can perhaps minimize potential future damage by not promoting fiddlewood in the landscape industry, taking fiddlewood out of the Maui county planting plan, and/or including it in a list of plants not to plant. People can keep their eyes open for fiddlewood, especially in natural areas, and alert USGS/BRD of new locations. Information can be shared with others including this report. Key contacts: United States Geological Survey - Biological Resources Division Forest Starr, Kim Martz and Lloyd Loope PO Box 369 Makawao, HI 96768 (808) 572-4472, (808) 572-4470 fstarr@hawaii.edu, kmartz@hawaii.edu, lloyd_loope@usgs.gov Hawai i State Department of Land and Natural Resources Division of Forestry and Wildlife Robert Hobdy, Richard Nakagawa 54 S. High St. Rm. 101 Wailuku, HI 96793 (808) 871-4084 Literature cited Evenhuis, N.L. and S.E. Miller, eds. 1997. Records of the Hawaii Biological Survey for 1996. Parts 1 and 2. Bishop Museum Occasional Papers 48, 49. Gerrish, G., and Mueller-Dombois, D. 1980. Behavior of native and non-native plants in two tropical rain forests on O'ahu, Hawaiian islands. Phytocoenologia, 8, 237-95. Hobdy, Robert. 1998. Personal communication with authors. March 9, 1998. Smith, C. 1998. University of Hawai'i Botany Department web page. Alien plants of Hawai'i. Citharexylum spinosum. www.botany.hawaii.edu/faculty/cw_smith/cit_spi.htm. Turner, R.J. Jr. and E. Wasson. 1997. Botanica. Mynah Publishing. NSW Australia. 1007 pp. Wagner, W.H., D.R, Herbst, S.H. Sohmer. 1990. Manual of the Flowering Plants of Hawai i. University of Hawai i press, Honolulu, Hawai i. Fiddlewood (Citharexylum spinosum) 5
Known global distribution of fiddlewood Know distribution of fiddlewood in the state of Hawaii, USA Fiddlewood (Citharexylum spinosum) 6
Mature fiddlewood tree - Makawao, Maui Fiddlewood leaves and flowers - Kula, Maui Known distribution of fiddlewood on the island of Maui, State of Hawaii Fiddlewood (Citharexylum spinosum) 7