Alien looks like a local but ruins environment Kia‘i Moku By Wendy Swee

Forest and Kim Starr, botanists with the U.S. Geological Survey, were completing a comprehensive weed survey on upcountry ranchland when they discovered a FOREST AND KIM STARR Photos small shrub they normally wouldn’t Spanish heath (left) looks much like the native pukiawe (whose flowers are greatly have given a second glance. “It looks magnified for the photo at right). However, on closer look, differences become apparent. Spanish heath has large, showy flowers, while pukiawe’s flowers are much very similar to the native pukiawe,” smaller. Spanish heath produces only dry capsules, while pukiawe has fleshy round reports Forest Starr. On closer in- pink fruit. The leaves on Spanish heath look like lime-green needles. Pukiawe has spection, they recognized the plant as spiky leaves, too, but they are flat, bluish-green, with parallel veins. Spanish heath (Erica lusitanica), a serious threat to native Hawaiian for- dumped garden waste, in transported the Spanish heath, the Maui Invasive ests and to rangelands. soil, and by wind and water. It can Species Committee requested an Spanish heath, native to south- also spread on the coats of animals or evaluation using the Hawaii Pacific western Europe, has a history of in- get tracked on hooves, boots, or tires. Weed Risk Assessment, a process vasiveness in Australia, Tasmania, Some of Maui’s most costly in- that uses the answers to questions and New Zealand. All of these places vaders were brought in as garden or- about a plant’s characteristics and have declared it a noxious weed. namentals. They include miconia, history elsewhere to generate a score. Though Spanish heath prefers full pampas grass, Australian tree ferns, This score has proven accurate in sunlight, it will also invade forests. It and tibouchina. Gardeners can pre- determining which plants are inva- can completely take over the shrub vent further threats by avoiding spe- sive 95 percent of the time. Based layer of native ecosystems, particu- cies like these and Spanish heath that on the HP-WRA score for Spanish larly in cool, moist climates. This is are known to escape. heath and its limited distribution on especially bad news for mauka Ha- As the Starrs discovered, Spanish Maui so far, concern about its spread waiian rainforests, which, unlike heath looks much like our native led MISC to add the plant to its tar- other rainforests worldwide, have an pukiawe (Leptecophylla tameia- get list. open canopy letting light down to a meia), also in the family Ericaceae. If you spot Spanish heath, please diverse shrub layer. Australia’s Co- Both shrubs have small spiky leaves contact the Maui Invasive Species operative Research Centre on Weed and a similar shape. However, on Committee at 573-MISC (6472). If Management reports that Spanish closer look, differences become ap- you suspect that a plant you are con- heath can also establish along road- parent: Spanish heath has large, sidering for your garden could be sides, requiring expensive control to showy flowers, while pukiawe’s invasive, check the Hawaii Pacific keep the view open. Pastures provide flowers are much smaller. Spanish Weed Risk Assessment tool website habitat to invade, too, as shown by heath produces only dry capsules, at http://www.botany.hawaii.edu/ the location of the plant’s first sight- while pukiawe has fleshy round pink faculty/daehler/WRA/ to see if it has ing on Maui. Thus it can affect com- fruit. The leaves on Spanish heath already been listed or to request an mercial ranching adversely. And are so curled they look like needles, evaluation. You can also contact since rainforests in Hawaii protect lime-green in color. Pukiawe has MISC for alternative planting sug- our water supply, all of its bad habits spiky leaves, too, but they are flat, gestions. Don’t let another beauty have a negative effect on our econ- bluish-green, with parallel veins. become Hawaii’s latest beast. omy. The native plant, pukiawe, in con- How could a garden shrub with trast to Spanish heath, produces only • Wendy Swee is the Education/ showy bell flowers be so very bad? a few seeds in each fruit, and these Outreach and Data Associate for the The same characteristics that make it must pass through a bird’s digestive Maui Invasive Species Committee. attractive as a garden plant are what system in order to germinate. Like She previously worked for the Ha- wai‘i Natural History Association at make it an invasive weed: it’s tough, other native plants, it harmonizes with the species in its environment, Haleakalā National Park and re- grows fast, lives a long time, pro- cently returned to Maui after work- duces millions of dust-like seeds that instead of dominating the landscape. Its uses in Hawaiian culture include ing as a historical interpreter on the can live in the soil for 4 years or mainland. “Kia‘i Moku,”(Guarding making leis with the fruit and dyeing more, and will grow even in infertile the Island) is prepared by the Maui soils. What’s more, even if a Spanish kapa cloth. In pre-contact days under Invasive Species Committee to pro- heath plant is burnt or broken, it will the kapu system, smudging an alii vide information on protecting the easily grow again. It readily colo- with smoke from burning pukiawe island from invasive plants and ani- nizes burned areas, reaching a den- would allow him or her to mingle mals that can threaten the island’s sity that can provide fuel for future with commoners. environment, economy and quality of fires. It can spread from seed in After the Starrs reported sighting life. As submitted to The Maui News. Published March 8, 2009. Page C7.