Eucalyptus bicostata, commonly known as eurabbie, is a significant species within the vast Eucalyptus genus, native to Australia. This tree is recognized for its imposing stature and distinctive features, making it a notable component of its natural ecosystems. The eurabbie is a large to very large forest tree, typically reaching heights of 30 to 50 meters, and occasionally exceeding 60 meters. Its growth habit is erect and stately, forming a substantial canopy. The juvenile leaves are opposite, sessile, and ovate to broadly elliptical, often exhibiting a glaucous or blue-green hue. As the tree matures, the adult leaves become alternate, petiolate, lanceolate to falcate, and are typically pendulous. These adult leaves are concolorous, meaning they are similar in color on both surfaces, and are usually a glossy green. The inflorescences are axillary, with umbels containing seven to eleven flowers. The flower buds are distinctive, characterized by two prominent ribs or keels running longitudinally along the operculum (the cap that covers the flower before it opens), which gives the species its scientific name, bicostata, meaning "two-ribbed." The operculum is conical to beaked. Following flowering, the fruit is a woody capsule, typically obconical or hemispherical, and also often exhibits two prominent ribs. The seeds are small and vary in color, often brown. The bark of Eucalyptus bicostata is typically smooth and shedding in long ribbons, often described as stocking-like on the lower trunk and smooth and greyish-white to cream or pale brown on the upper trunk and branches. Eucalyptus bicostata is primarily found in the Great Dividing Range of New South Wales and Victoria, Australia. It thrives in a variety of habitats, commonly growing in tall, wet sclerophyll forests on fertile soils, often derived from basalt or granite. It prefers moist, well-drained sites and can be found on slopes and in valleys. While it is a species of temperate Australia, its cultivation requirements generally include a climate with adequate rainfall and protection from prolonged, severe frosts, especially when young. The eurabbie holds ecological importance as a habitat and food source for native fauna. Its timber has been utilized, though it is not as widely exploited as some other eucalypt species. The species is also valued ornamentally for its impressive size and attractive foliage and bark, though its large stature makes it suitable only for extensive landscapes or parklands. There is no widespread documented culinary or medicinal use for Eucalyptus bicostata. An interesting characteristic of Eucalyptus bicostata is its adaptation to fire. Like many eucalypts, it possesses lignotubers, which are woody swellings at the base of the stem that contain dormant buds. These allow the tree to resprout vigorously from the base after fire has cleared the understory and damaged the canopy. The glaucous nature of its juvenile foliage may also play a role in reducing water loss or deterring herbivores.