Eucalyptus represents a vast and diverse genus of flowering trees and shrubs, predominantly native to the Australian continent. With over 700 species, this group is a defining feature of the landscape. Understanding these alternate names requires looking into the tree’s physical characteristics and close botanical relatives, which are often confused.
The Definitive Alternative: Gum Tree
The most common alternative name for a Eucalyptus tree is the Gum Tree. This moniker is frequently used interchangeably with the scientific genus name, especially in Australia, where the tree is iconic.
The name originates from the sticky, resinous substance that many species exude from their trunks when damaged. This substance is technically known as kino, a dark, astringent exudate that hardens upon exposure to air. The flow of this sap resembles a thick gum, which led early observers to adopt the common name. Although not all species exhibit this flow, “Gum Tree” became a generic term for the entire Eucalyptus genus. Species like the River Red Gum (Eucalyptus camaldulensis) and Blue Gum (Eucalyptus globulus) carry it in their common names.
Scientific Identity and Related Names
The scientific identity of Eucalyptus is complex because the genus name is often used broadly to describe other closely related trees. Botanists collectively refer to the entire group as “eucalypts,” which includes Eucalyptus and two other significant genera within the Eucalypteae tribe. Public confusion about alternate names often arises because people commonly call any member of this group a Eucalyptus.
The two main genera often mistaken for true Eucalyptus trees are Corymbia and Angophora. Corymbia species, commonly known as the Bloodwoods, were reclassified out of Eucalyptus. They are distinguished by their unique flower clusters, but they also produce the characteristic kino. This shared trait of exuding kino is why the common name “Gum Tree” persists across both genera.
The third related genus is Angophora, known by the common names Apple Gums or simply Apples. These trees are botanically distinct because their flower buds lack the fused cap, or operculum, which defines the Eucalyptus genus. This lack of an operculum is a key scientific difference. While “Gum Tree” is the primary common synonym, names like “Bloodwood” and “Apple Gum” represent distinct, yet often misidentified, botanical cousins.