WHILE IN AUSTRALIA we saw diverse varieties of eucalyptus trees, and a wide variety grows here on the peninsula in the Stanford campus.
A notable feature is their bark - sometimes shaggy, sometimes stringy, sometimes flaky and smooth. Known as “gum trees” for the sap that exudes from the damaged bark, the trees stand tall and massive, with large limbs for harvesting. The leaves and flowers are a favorite of the Australian koala since the oils are necessary for the koala’s digestion.
Their history dates back to the Gold Rush when the trees were imported as a quick-growing renewable source for timber and charcoal for the kiln ovens that processed gold ore. However the new variety trees did not compare to the old eucalyptus of Australia and the wood split, warped, and burned too quickly. In addition, eucalyptus forests displaced native plants and didn’t support local animals, so the forests have been gradually cut down in favor of native trees.
Eucalyptus flowers produce huge amounts of nectar that attracts birds and insects. The name eucalyptus is Greek for "well-covered" describing flowers with multiple stamens but no petals to attract insects.
However, stands of the fast-growing trees provide excellent windbreaks for highways and farms in the central valley, and they're highly regarded as ornamental shade trees in cities and gardens. Just don't let them get too tall!