Rainbow Eucalyptus Tree: Eucalyptus deglupta

The rainbow eucalyptus is one of the few trees that looks painted. Streaks of green, blue, purple, orange and maroon run down its trunk, and none of it is artificial. Here is what the tree is, how it acquires its colours, and where it grows.

The Rainbow Eucalyptus is known for its naturally colourful trunk.

What Is the Rainbow Eucalyptus?

Eucalyptus deglupta belongs to the Myrtaceae family and is also called rainbow gum or Mindanao gum. Wikipedia describes it as a fast-growing evergreen that typically reaches 60 to 78 metres in its native range, though trees grown elsewhere are usually smaller and less colourful, according to WorldAtlas.

Two things set it apart from other eucalypts. Most of the genus lives in Australia’s drier landscapes, but this species grows in wet tropical rainforests. It is also the only eucalyptus whose natural range reaches into the Northern Hemisphere.

Why Does the Bark Change Colour?

The tree sheds its outer bark in strips throughout the year, not all at once. Each strip exposes a fresh layer underneath, and that layer is bright green at first. As it ages, the green fades and other colours build up. ZME Science describes the pattern as chlorophyll breaking down while tannins accumulate. Botanist David Lee of Florida International University, quoted by Explorersweb, explains that exposure to air triggers tannin build-up, which helps protect the tree from fungi.

The Colour Sequence

A typical strip moves from green to blue, then purple, orange and finally maroon before it peels away and the cycle restarts. Because neighbouring strips peel at different times, one trunk can show several stages at once. That is the whole rainbow effect, and it also explains why no two trees look alike.

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Different stages of bark development create the unusual colours of the tree.

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Where Does Rainbow Eucalyptus Grow?

Kew’s Plants of the World Online lists its native range as the Philippines, New Guinea, Sulawesi, Maluku, the Lesser Sunda Islands and the Bismarck Archipelago. It needs warm, wet conditions and does not tolerate frost. Outside its range, it is planted as an ornamental in frost-free places such as Hawaii, Southern California, Texas and Florida, Wikipedia notes.

What Is It Used For?

Mostly paper. Wikipedia says the species is grown in plantations mainly for pulpwood used to make white paper, and it is used far less often as timber. ZME Science adds that deforestation in its native regions is the main threat to wild trees.

Rainbow Eucalyptus Facts

• Scientific name: Eucalyptus deglupta
• Other names: rainbow gum, Mindanao gum
• Family: Myrtaceae
• Type: fast-growing evergreen
• Habitat: wet tropical rainforest
• Colour sequence: green, blue, purple, orange, maroon
• Main use: pulpwood for paper

More Remarkable Trees on Ritebook

For another unusual tree, read about Pando, the Trembling Giant, or the Pisonia tree and its sticky seeds. Colour in nature also appears at Lake McDonald. More like these sit under the Tree and Natural Wonders labels.

Eucalyptus deglupta is commonly known as the Rainbow Eucalyptus.

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Fresh and older layers of bark can display different colours.

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The bark can change from bright green to warmer shades as it matures.

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Older bark peels away to reveal younger layers underneath.

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Several shades may appear together on the same tree.

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Eucalyptus deglupta naturally grows in warm, wet tropical regions.

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The colourful appearance develops naturally as the bark peels off.

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Conclusion

The rainbow eucalyptus derives its colours from a simple cycle of peeling, ageing and renewal. That cycle, plus its rainforest home and Northern Hemisphere range, makes it unlike any other tree in its genus.

Sources: Wikipedia: Eucalyptus deglupta · Kew Plants of the World Online · ZME Science · Explorersweb · WorldAtlas