Eucalyptus saligna

Sydney Blue Gum or Blue Gum

Family: Myrtaceae

A large tree that can become a giant, growing to 60 m tall and forms a lignotuber. Found in areas which receive between 800 to 1200 mm of rainfall, on either clay-loams or soils of volcanic origin, within 120 km of the coastline. Grows to as far south as Port Jackson, north along the coast to Maryborough in central Queensland. Then there are disjunct populations further north up to Cairns.

It does form an integral part of the endangered blue gum high forest ecological community in the Sydney region.

Populations found south of Port Jackson are now not considered to be E. saligna but rather E. saligna x botryoides.

There are some spectacular remnant specimens in Sydney’s northern suburbs (Pymble, Pennant Hills, Wahroonga etc.), many of which persist in weed-infested or fragmented bushland.

The bark is smooth, pale grey or white with usually some rough brownish bark at the base of the trunk (referred to a ‘sock’).

Juvenile/coppicing growth has lance-shaped (lanceolate) to egg-shaped (elliptic) or oblong leaves, that are paler on the lower surface, to 120 mm long and to 40 mm wide. Adult leaves are arranged alternately, glossy green, paler on the lower surface, lance-shaped to curved, to 190 mm long and to 40 mm wide, on a petiole to 30 mm long.

The flower buds are arranged in leaf axils in groups (umbellasters) of seven, nine or eleven on an, the individual buds sessile or on pedicels up to 5 mm long. Mature buds are spindle-shaped, oval or diamond-shaped, to 10 mm long and to 5 mm wide with a conical or beaked operculum/calyptra.

Flowering occurs from December to March and the flowers are white.

The capsule is a woody cylindrical, conical or cup-shaped capsule to 9 mm long and to 7 mm wide with the valves protruding above the rim and an outward direction from the centre.

In the garden

A very spectacular tree if grown in the right spot. Can grow a very straight gum-trunk up to 30 or more metres tall with the. Obviously, it needs a large open space to thrive. It may serve as a nice specimen plant in a park, a large garden any may be planted in a copse for revegetation purposes. Not suitable for small residential gardens. It prefers an enriched loam to clay-loam soil.

Trees can live for over two hundred years. They can grow remarkably quickly when planted from a seedling or tubestock.

The grey-headed flying fox (Pteropus poliocephalus) eats the flowers and the crimson rosella (Platycercus elegans) eats the seeds.

A Koala food tree. This species is one of 27 more common eucalypt and corymbia plants eaten by them.

Eucalypts can suffer problems from, caterpillars, leaf eating beetles, psyllids and borers to name a few. In undisturbed conditions, the numbers of eucalypt-feeding insects and their predators and parasites are in balance, so that they rarely cause tree death and most trees quickly recover from attack. In a home situation nature can get out of balance.

Propagation

Eucalyptus can be propagated by seeds which is most common method or grafting.

Cuttings are difficult to start, but can be used in some species. For further information refer to: http://anpsa.org.au/APOL2007/sep07-s1.htm

Other information

Eucalyptus is one of three similar genera that are commonly referred to as “eucalypts”, the others being Corymbia and Angophora.
Refer to these two links for more clarification:
http://anpsa.org.au/eucal1a.html
http://anpsa.org.au/APOL2/jun96-5.html

Plants regenerate from lignotubers and epicormic shoots after fire. They will also regenerate from the seedbank.

E. saligna has an attractive rose-coloured timber which is suitable for commercial production due to its rapid early growth under favourable conditions, as well as its ease to work with.

Eucalyptus – from Greek, eu, “well” or “true” and calyptus, referring to the calyptra (καλύπτρo) or operculum, which is a bud cap or covering which covers the developing flowers. The calyptra is a fusion of petals and/or sepals and is shed when the flower opens, leaving a flower with many stamens (staminate) surrounding one female part (carpel).
saligna – Latin for ‘willow like’ (genus Salix) referring to the long somewhat-weeping leaves presumably.

Not considered to be at risk in the wild.

“Field Guide to Eucalypts Vol 1 South Eastern Australia’ M.I.H.Brooker and D.A.Kleinig. Blooming Books.
https://www.anbg.gov.au/gnp/trainees-2016/eucalyptus-saligna.html
https://en.wikipedia.org/wiki/Eucalyptus_saligna
https://en.wikipedia.org/wiki/Eucalyptus
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Eucalyptus~saligna

By Jeff Howes