eucalyptus

Eucalyptus is a genus of more than 700 species of flowering trees and shrubs in the myrtle family, Myrtaceae. Native to Australia and nearby islands, eucalypts are distinguished by evergreen leaves that are often rich in essential oils and by bark patterns that may shed in patches. The genus includes a broad range of forms, from tall forest trees to small, compact shrubs, many of which are cultivated worldwide for wood and ornament.

Description and biology: Leaves are typically lance-shaped and arranged alternately; juvenile foliage may be opposite. Flowers appear in clusters and lack petals in most species, with the showy parts being numerous stamens. The fruit is a woody capsule, commonly called a gumnut. Eucalypts are fast-growing, with some species capable of resprouting after fire and, in certain types, possessing reservoirs of buds in lignotubers.

Distribution and uses: Native to Australia, eucalypts have been widely introduced across the world for timber, pulp, soil stabilization, and ornamental purposes. They are common in Africa, Europe, the Americas, and Asia. In some regions non-native populations are invasive and can alter water use and fire regimes. Eucalyptus oil, particularly cineole, is extracted from the foliage and used in medicines, fragrances, and pest control. Flowers provide nectar for honey.

Ecology and management: While valued for rapid growth and economic uses, eucalypts can affect native ecosystems when established outside their natural range. Responsible planting involves selecting regionally suitable species, managing water and fire risk, and monitoring ecological impacts.