Eucalyptus

The koala's food and the tallest flowering tree

Eucalyptus is Australia's tree, and koalas eat only its leaves! The leaves are full of fragrant oil — cold remedies are made from it. Some eucalyptus trees grow 100 metres tall — the tallest flowering trees in the world. Eucalyptus isn't afraid of fire: after a bushfire, new shoots burst out from under the bark. Its bark peels off every year.

Eucalypts (over 700 species) make up 75% of Australia's forests; Eucalyptus regnans (mountain ash) is the tallest flowering tree in the world at 100 m ('Centurion', Tasmania, 100.5 m). The leaves hold essential oil (eucalyptol) — an antiseptic, toxic to most animals; koalas digest it thanks to special liver enzymes. Fire ecology: oily leaves burn fast, but the lignotuber (root swelling) and dormant buds regrow after fire, and seeds open only after burning. Fast-growing (2 m a year), it covers 20 million ha of plantations worldwide (paper, timber), but drinks a lot of water and crowds out native species. The 'blue haze' of eucalyptus oil gave the Blue Mountains near Sydney their name. Trial plantings exist in Uzbekistan's Surkhandarya.

Fun facts

• The tallest eucalyptus is 100.5 m — like a 30-storey building.
• Eucalyptus seeds open only after a bushfire.
• The blue haze of eucalyptus oil named the Blue Mountains near Sydney.