By Winnie Singeo
What tall, stately tropical tree has a multicolored trunk that looks like someone has poured cans of various colored paint on it?
It's the Eucalyptus deglupta, or Mindanao gum tree. It's also called the rainbow-bark eucalyptus.
The rainbow-colored trunk is the result of thin strips of bark that continually peel off, exposing new layers of pink, orange, lime to dark green, violet and blue beneath.
There are several hundred eucalyptus species, most of which are native to Australia. One of the exceptions is the Mindanao gum, which can be found in the Philippines, Papua New Guinea and other western Pacific islands.
The Mindanao gum is a fast-growing tree, known to gain 5 to 8 feet in height per year, and can grow to 8 feet wide. It is one of the tallest and largest trees in the rainforests of the Philippines, towering to heights of more than 100 feet.
The Mindanao gum was first introduced to Hawai'i for reforestation in 1929 at Wahiawa Botanical Garden. From its beginning in Wahiawa, the Mindanao gum was distributed and now grows throughout the Islands.
Eucalyptus trees are generally known as gum trees because many species produce oils and gummy resins. The leaves of some species are more fragrant than others, and the scent varies.
About 25 species of eucalyptus trees produce oils used for medicinal, industrial and other commercial purposes. The oils are used in a multitude of ways: cleaning products, aroma therapy, liniments, and in very small amounts, in food supplements and cough drops.
Eucalyptus leaves are the favorite food of the Australian koala. However, an essential oil from the leaves is considered to be a powerful natural disinfectant, which is toxic in large quantities. The koala are relatively tolerant of the toxic effects. Still, they sample the leaves of different trees and tend to eat the leaves with low toxicity.
Although there are other eucalyptus that produce more dense and showy wood, it is the absence of the gummy resins that make the timber of the Mindanao gum useful in general construction, for poles and posts, furniture, and pulp and paper products.
Even without its commercial usefulness, the Mindanao gum tree is an eye-catching beauty that makes a gorgeous addition to the landscape.
Tip: Visit Wahiawa or Foster Botanical Garden to see the Mindanao gum tree.
Winnie Singeo is the director of Honolulu botanical gardens. Reach her at firstname.lastname@example.org. Foster Botanical Garden, 50 N. Vineyard Blvd., is open daily except Christmas and New Year's days from 9 a.m. to 4 p.m. Information: 522-7066.