With its vivid coloration and distinctive shape, the Rainbow Eucalyptus tree is one of nature’s most unique treasures.
Native to Northern Australia, Papua New Guinea, Indonesia, Philippines, and several other countries in Oceania region at northern regions of latitude 20° south to northern Australia and Lord Howe Island. It has been introduced into tropical areas around the world where it has become a valuable ornamental plant in parks and gardens.
These trees, also known as the Mindanao gum or rainbow gum, can reach up to 250 feet (76 m.) tall in their native environment. The trunks of these majestic giants can be six feet (two meters) across and usually divide close to the ground into several primary branches which then curve upward. Their bark is smooth with vertical fissures; it is brown-grey to grey-black in color.
In their native territories, Rainbow Eucalyptus trees may live more than 500 years! When grown outside of this ideal habitat though they have a much shorter lifespan. For example, one tree at San Francisco’s Golden Gate Park lived 136 years.
The Rainbow Eucalyptus tree grows best in moist climates that do not experience dry summers or freezing conditions, but they can die if left standing in water for long. They grow well near bodies of water but do not like to stand in it. They will grow faster and live longer if they receive plenty of water during their first few years. Because these trees are so long-lived, the growth rate slows down as the tree matures. Growth rings become more visible once a branch has reached its maximum size and stopped growing upward.
The Rainbow Eucalyptus is virtually free from pests and diseases, though felled trunks can rot away quickly due to the presence of resin, thus making them unsuitable for timber uses. This rich sap does not usually coagulate when exposed to air and hence makes inferior quality rubber compared with that from other sources.
Rainbow Eucalyptus trees were first encountered in the Philippines during Magellan’s expedition in 1521 when his crew observed locals making canoes from their wood. The Rainbow Eucalyptus is popular among growers and sellers of cut flowers, such as orchids and roses because it has a long vase life. Despite being very hard and durable after it has been seasoned, Rainbow Eucalyptus trees are rarely used to construct buildings because they tend to be twisted and warped and therefore “crook” when cut into lumber.
The tree exudes a heavy, dark red resin (kino) which is also called Eucalyptus deglupta gum, although not actually a true gum. When dissolved in alcohol resin makes what is called “Pine Oil”, also known as “Para Oil” or “Pine Tar”. The Eucalyptus deglupta tree resin is antimicrobial, anti-inflammatory, antiseptic, and antibacterial. This means the resin has many varied uses in medicine. It has been used successfully to treat gangrene of the feet caused by poor circulation in patients with diabetes mellitus.
The rainbow eucalyptus, on the other hand, is a highly valuable commercial commodity that has nothing to do with its color. The tree is commonly utilized at tree plantations since it provides excellent pulpwood—the fundamental component in producing white paper. So next time you reach for a blank sheet of paper, think about how much more colorful it might have been originally.
The Rainbow Eucalyptus is one of the most beautiful trees around!