Rainbow Eucalyptus, Rainbow Gum-Eucalyptus deglupta
-4 things you may not know about this Kauai plant
1. What is it? The Rainbow Eucalyptus is a member of the myrtle family and is large, fast-growing, broadleaved evergreen tree. It grows primarily in lowlands and lower rainforest areas from sea level up to about 2000'. The tree can grow up to 250 feet tall with up to a 6' trunk diameter. The leaves are acuminate or lance shaped and up to 6" long, arranged in opposite pairs and have a pleasant odor when crushed. The Rainbow Gum is fast growing and has shallow butressed roots, making it prone to being uprooted in stronger winds. The flower buds are arranged in branches either in leaf axils, or on the end of branchlets, each branch with groups of seven buds blooming various times during the year. Rainbow Eucalyptus won't tolerate any cold weather(which isn't a problem here in Hawaii-obviously) and like a lot of precipitation and full sun. The real attention getter of this tree is the bark which peels off the trunk in vertical strips revealing rainbow of streaks of pale green, red, orange, gray and purple-brown. Once you see a grouping of them, you will know what I'm talking about. The most dramatic and easily accessible groves is along the main road edging the golf course in Princeville. There are as many as 90 other varieties of Eucalyptus that grow in Hawaii. One of Kauai’s iconic locations, the “Tree Tunnel” or "Tunnel of Trees" is about a mile long stretch of Maluhia Road leading to Koloa and Poipu. Here the visitor is greeted by this canopy of Swamp Mahagony Eucaluptus (Eucalyptus robusta).
2. Where did it come from? The Rainbow Eucalyptus is native to the Philippines, Indonesia, and Papua New Guinea. It is the only Eucalyptus species that usually lives in rainforest, and is one of only four eucalypt species out of more than seven hundred that do not occur in Australia. It was introduced to Hawaii, arriving from the Philippines in 1929 and was planted in the Wahiawa Botanical Garden on Oahu as part of a reforestation movement. It may have reached the other islands as a shade tree or to help soil erosion. It is grown for making white paper in the Philippines, but is also a beautiful wood for furniture, flooring, boats, and plywood. Medicinally, the leaves have been used as an antiseptic and deodorant, as tea for cough and asthma, to combat Malaria and lung infections. The oil has been used for sterilizing surgical tools, as a veterinary medicine for influenza in horses, distemper in dogs and for parasitic infections. The burning of the leaves also works as a repellent.
3. When is the best time for collecting?
We collect both the bark curls, and seed cones from several different varieties. The Rainbow Eucalyptus has dried bark ranging from red to maroon Red Gum Eucalyptus tends to be more orange. The seed cones look very similar for both the Rainbow and Red Gum, but the Swamp Mahogany’s cones are 3-4 times the size. I can usually find both bark curls and seed cones whenever I need them and usually after a few windy days the supply is quite abundant.
4. How are the collected plant parts used?
We use the bark curls and larger seed cones as a decorative element on both baskets and pouches. The smaller seed cones are used as a decoration on the Budvases
*Amy is a University of Hawaii Certified Master Gardener Emeritus, has a Bachelor of Science-Landscape Horticulture degree from Ohio State, has been a volunteer tour guide at NTBG, and is a self-proclaimed "plant nut"! She and her husband Ron have been making and selling their baskets for more than 20 years.