| Gum trees, Eucalyptus blaxlandii, Eucalyptus piperita, Eucalyptus fastigata, Eucalyptus stricta|
Eucalyptus oreades, commonly known as the Blue Mountains ash, is a species of eucalyptus native to eastern Australia.
Eucalyptus oreades Wikipedia
First collected by Richard Thomas Baker and Henry George Smith at Adelina Falls near Lawson in the Blue Mountains on 22 April 1899, Eucalyptus oreades was described by Baker. The species name is derived from Ancient Greek oreades "of the mountains". Other common names include smooth-barked mountain ash and white ash.
Eucalyptus oreades can reach 40 m in height, with a trunk up to 1.8 m (6 ft) in diameter at chest height. The smooth pale bark is deciduous, shedding in strips and leaving a 'skirt' of thicker bark around the trunk base. The lanceolate (spear-shaped) green leaves measure 11–17 cm (4.4-6.8 in) long and 1.5–2.3 cm (0.6–0.9 in) wide, and the same colour on both sides. The white flowerheads are arranged in groups of seven, and are in bloom in January and February.
The range is from Mittagong in the Southern Highlands north to the Queensland border. It is widespread in the Blue Mountains, with a somewhat scattered distribution elsewhere. It is found on sandstone soils in the Blue Mountains, and red clay loams elsewhere. In the Blue Mountains, it is found on steep slopes and ridges, on southern or eastern aspects, from elevations of 600 to 1,200 metres (2,000 to 3,900 ft) and annual rainfall of 900 to 1,400 millimetres (35 to 55 in). The habitat is open eucalypt forest, and associated species include silvertop ash (E. sieberi), narrow-leaved peppermint (E. radiata), broad-leaved peppermint (E. dives), Sydney peppermint (E. piperita), Blaxland's stringybark (E. blaxlandii), snappy gum (E. racemosa), messmate stringybark (E. obliqua), tallowwood (E. microcorys), and New England blackbutt (E. andrewsii).
Eucalyptus oreades is unusual for a eucalypt in that it is sensitive to bushfire, and often succumbs, with recruitment coming from the seeds stored in the canopy seedbank. Mature trees over 20 years of age do have a skirt of thicker corky bark which helps them resist low-intensity fires.
Very fast growing in cultivation, Eucalyptus oreades is grown in plantations for timber, both in Australia and overseas in New Zealand and South Africa.