Eucalyptus () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of Eucalyptus are trees, often mallees, and a few are shrubs. Along with several other genera in the tribe Eucalypteae, including Corymbia and Angophora, they are commonly known as eucalypts or "gum trees". Species of Eucalyptus have bark that is either smooth, fibrous, hard, or stringy and leaves that have oil glands. The sepals and petals are fused to form a "cap" or operculum over the stamens, hence the name from Greek eû 'well' and kaluptós 'covered'.
Most species of Eucalyptus are native to Australia, and every state and territory has representative species. A few species are native to islands north of Australia, and a smaller number are only found outside the continent. Eucalypts have been grown in plantations in many other countries because they are fast-growing, have valuable timber, or can be used for pulpwood, honey production, or essential oils. In some countries, however, they have been removed because of the danger of forest fires due to their high flammability.
Description
Eucalypts vary in size and habit from shrubs to tall trees. Trees usually have a single main stem or trunk but many eucalypts are mallees that are multistemmed from ground level and rarely taller than 10 metres (33 feet). There is no clear distinction between a mallee and a shrub but in eucalypts, a shrub is a mature plant less than 1 m (3 ft 3 in) tall and growing in an extreme environment. Eucalyptus vernicosa in the Tasmanian highlands, E. yalatensis on the Nullarbor and E. surgens growing on coastal cliffs in Western Australia are examples of eucalypt shrubs.
The terms "mallet" and "marlock" are only applied to Western Australian eucalypts. A mallet is a tree with a single thin trunk with a steeply branching habit but lacks both a lignotuber and epicormic buds. Eucalyptus astringens is an example of a mallet. A marlock is a shrub or small tree with a single,...
