Eucalyptus saligna, commonly known as the Sydney blue gum or blue gum, is a species of medium-sized to tall tree that is endemic to eastern Australia. It has rough, flaky bark near the base of the trunk, smooth bark above, lance-shaped to curved adult leaves, flower buds in groups of seven, nine or eleven, white flowers and cylindrical to conical or cup-shaped fruit.
Description
Eucalyptus saligna is a tree with a straight trunk that typically grows to a height of, rarely to, a dbh of, and forms a lignotuber. The trunk has smooth pale grey or white bark with of rough brownish bark at the base. Young plants and coppice regrowth have lance-shaped to egg-shaped or oblong leaves that are paler on the lower surface, long and wide. Adult leaves are arranged alternately, glossy green, paler on the lower surface, lance-shaped to curved, long and wide, on a petiole long. The flower buds are arranged in leaf s in groups of seven, nine or eleven on an unbranched peduncle long, the individual buds sessile or on pedicels up to long. Mature buds are spindle-shaped, oval or diamond-shaped, long and wide with a conical or beaked operculum. Flowering occurs from December to March and the flowers are white. The fruit is a woody cylindrical, conical or cup-shaped capsule long and wide with the valves protruding above the rim.
Sydney blue gum is generally found within of the coastline in its range from Sydney to Maryborough in central Queensland. To the northwest, it is found in disjunct populations in central Queensland, including in Eungella National Park, Kroombit Tops, Consuelo Tableland, Blackdown Tableland and Carnarvon Gorge. It grows in tall forests in more sheltered areas, on clay or loam soils, and alluvial sands. It is a component of the endangered blue gum high forestecological community in the Sydney region. Populations found south of Sydney are now not considered to be E. saligna. Associated trees include blackbutt, grey ironbark, mountain blue gum, flooded gum, tallowwood, thin-leaved stringybark, manna gum, river peppermint, grey gums, rough-barked apple, spotted gum, turpentine, brush box and forest oak. South of Sydney Harbour and the Parramatta River, pure stands of E. salignagive way to hybrid populations with bangalay.
Ecology
Eucalyptus saligna regenerates by regrowing from epicormic buds on the trunk and lower branches after bushfire. Trees live for over two hundred years. The grey-headed flying fox eats the flowers, the koala eats the leaves, and crimson rosella eats the seed. The longhorn beetle species Paroplites australis, Agrianome spinicollis and Tessaromma undatum have been recorded from the Sydney blue gum. The presence of the territorial and aggressive bell miner and psyllid insects is correlated with dieback of the canopy of E. saligna, a syndrome which has been termed bell-miner-associated dieback, though the exact mechanism remains unclear. After colonization by Glycaspis, E. salinga may then be infested by the ambrosia beetleAmasa truncata.
Uses
The wood of this species is heavy, fairly hard, coarse, even textured and reasonably easy to work. It is used for general building construction, panelling, and boat-building, and is highly prized for flooring and furniture because of its rich dark honey colour.
