Blue Gum

Eucalyptus globulus is native to southeastern Australia and Tasmania.

• Found naturally in Tasmania and southern Victoria, particularly in the Otway Ranges, Strzelecki Ranges, and parts of Gippsland
• Occurs in wet sclerophyll forests and coastal areas from sea level to approximately 500 meters elevation
• Thrives in cool, moist climates with annual rainfall of 600 to 1,400 mm
• First described by the French botanist Jacques Labillardière in 1800 from specimens collected in Tasmania during the d'Entrecasteaux expedition
• The species was introduced to California in the 1850s during the Gold Rush era, where it was planted extensively for timber, windbreaks, and fuel
• Blue Gums planted in California have reached heights exceeding 60 meters (200 feet), making them the tallest trees in the state outside of the coastal redwoods
• In Portugal and Spain, Blue Gum plantations cover vast areas and are the backbone of the European pulp and paper industry
• The species has become naturalized and often invasive in California, Portugal, Spain, South Africa, and parts of South America

Eucalyptus globulus is a large to very large, fast-growing evergreen tree.

Trunk and Bark:
• Tall, straight trunk, typically reaching 30 to 55 meters in height (exceptionally over 90 meters) with a DBH of 1 to 2.5 meters
• Bark smooth throughout, shedding in long strips, grayish-white to cream, often with blue-gray or greenish tints
• Older bark accumulates in curly ribbons at the base of the trunk

Juvenile Foliage:
• Juvenile leaves are sessile (stalkless), opposite, broadly lanceolate to ovate, 10 to 15 cm long and 5 to 10 cm wide
• Strikingly glaucous (blue-gray), giving the tree its common name "Blue Gum"
• Covered in a waxy bloom that rubs off easily

Adult Leaves:
• Lanceolate to narrowly lanceolate, 15 to 30 cm long and 2 to 4 cm wide
• Dark green, glossy, alternate, thick and leathery, strongly aromatic
• Rich in essential oils, particularly 1,8-cineole (60 to 80% of leaf oil)

Flowers:
• Solitary or in clusters of up to 3 in the leaf axils
• Buds large, glaucous, with a warty, hemispherical operculum (bud cap) 6 to 12 mm long
• Flowers large, 3 to 4 cm in diameter, with a mass of white to cream stamens
• Copious nectar production attracts bees, birds, and bats

Fruit:
• Large, woody, globose to urceolate (urn-shaped) capsules, 12 to 18 mm long and 15 to 25 mm wide
• Valves 3 to 5, prominently exserted
• Contain numerous small seeds

Eucalyptus globulus is a dominant species in wet sclerophyll forests of southeastern Australia and Tasmania.

• Occurs in wet forests where it forms the canopy over a dense understory of ferns, tree ferns (Dicksonia antarctica), and broadleaf shrubs
• Flowers prolifically, producing abundant nectar that supports Tasmanian native bees, honeyeaters, and the critically endangered swift parrot (Lathamus discolor)
• Hollows in old-growth trees provide essential nesting sites for numerous species including the Tasmanian masked owl, eastern pygmy possum, and various microbats
• Fire-adapted — mature trees survive moderate fires through thick bark and epicormic resprouting; intense crown fires can kill stands, which then regenerate from seed
• Litter decomposes slowly due to high lignin and phenolic content, forming deep accumulations that influence fire behavior
• Fast growth allows rapid post-fire regeneration in native forests
• As an introduced species, Blue Gum significantly alters ecosystems — it depletes soil moisture, suppresses understory vegetation through allelopathy and shading, and increases fire risk due to accumulated bark and oil-rich litter
• In California, Blue Gum groves have displaced native oak woodland and coastal scrub communities
• In Portugal and Spain, plantations have reduced stream flow and lowered water tables

Blue Gum is not considered threatened in its native range.

• Listed as Least Concern on the IUCN Red List
• Common and widespread in Tasmania and southern Victoria
• However, old-growth Blue Gum forests in Tasmania are threatened by logging for woodchips and timber
• The species is protected in national parks and reserves including Tasmania's Southwest National Park and Hartz Mountains National Park
• Genetic conservation is important due to the vast plantations worldwide — maintaining diversity in native populations ensures a genetic reservoir for future breeding
• In its introduced range, Blue Gum is managed as an invasive species in many areas, with active removal programs in parts of California, South Africa, and Portugal